title: Better errors message if template is missing
body: <p>If a template is missing deep inside the rendering of a django template, I get a exception like below.</p>
  
  <p>After searching very long I found the bogus part:</p>
  
  <pre><code> {% include form.template_name %}
  </code></pre>
  
  <p>form.template_name was empty in my context.</p>
  
  <p>How can I find the relevant template name without searching for hours?</p>
  
  <p>I am missing a traceback like for normal python code. "Normal" python tracebacks show me the file and line which contain the bug.</p>
  
  <pre><code>/home/foo_fm_d/bin/python /usr/local/pycharm-community-4.5/helpers/pycharm/utrunner.py /home/foo_fm_d/src/foo-time/foo_time/tests/unit/views/user/test_preview_of_next_days.py::EditTestCase::test_preview_of_next_days true
  Testing started at 09:26 ...
  
  Error
  Traceback (most recent call last):
    File "/home/foo_fm_d/src/foo-time/foo_time/tests/unit/views/user/test_preview_of_next_days.py", line 11, in test_preview_of_next_days
      self.admin_client.get(url)
    File "/home/foo_fm_d/src/djangotools/djangotools/utils/testutils.py", line 275, in get
      response = super(Client, self).get(path, data, **extra)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/test/client.py", line 473, in get
      response = super(Client, self).get(path, data=data, **extra)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/test/client.py", line 280, in get
      return self.request(**r)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/test/client.py", line 444, in request
      six.reraise(*exc_info)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 137, in get_response
      response = response.render()
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/response.py", line 105, in render
      self.content = self.rendered_content
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/response.py", line 82, in rendered_content
      content = template.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 140, in render
      return self._render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 134, in _render
      return self.nodelist.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
      bit = self.render_node(node, context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
      return node.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 123, in render
      return compiled_parent._render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 134, in _render
      return self.nodelist.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
      bit = self.render_node(node, context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
      return node.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 123, in render
      return compiled_parent._render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 134, in _render
      return self.nodelist.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
      bit = self.render_node(node, context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
      return node.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 62, in render
      result = block.nodelist.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
      bit = self.render_node(node, context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
      return node.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 88, in render
      output = self.filter_expression.resolve(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 585, in resolve
      obj = self.var.resolve(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 735, in resolve
      value = self._resolve_lookup(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 789, in _resolve_lookup
      current = current()
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 72, in super
      return mark_safe(self.render(self.context))
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 62, in render
      result = block.nodelist.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
      bit = self.render_node(node, context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
      return node.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 62, in render
      result = block.nodelist.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
      bit = self.render_node(node, context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
      return node.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 62, in render
      result = block.nodelist.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
      bit = self.render_node(node, context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
      return node.render(context)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 166, in render
      template = get_template(template_name)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader.py", line 138, in get_template
      template, origin = find_template(template_name)
    File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader.py", line 131, in find_template
      raise TemplateDoesNotExist(name)
  TemplateDoesNotExist
  
  
  Process finished with exit code 0
  </code></pre>
  
  <p><strong>Update</strong></p>
  
  <p>My personal background: Up to now I avoid django templates since sometimes exceptions get silently ignored and tracebacks like this make the debugging process feel like wearing heavy shoes made of concrete.</p>
  
  <p>I try to get get rid of my prejudices. Or least find a way how to get better error messages from templates.</p>
  
  <p><strong>Update II</strong></p>
  
  <p>I see the traceback via a unittest inside pyCharm. I don't read the result of the view. The "webbrowser" Client calls the view. I set TEMPLATE_DEBUG=True, but the result is the same.</p>