title: CMake output name for dynamic-loaded library?
body: <p>I'm trying to write cmake rules to build dynamic-loaded library for python using boost.python on linux. I'd like to use 'foo' for python module name. So, the library must be called <code>foo.so</code>.
  But by default, cmake uses standard rules for library naming, so if I write</p>
  
  <pre><code>add_library(foo foo.cpp)
  </code></pre>
  
  <p>I will get <code>libfoo.so</code> on output.
  Even <code>set_target_properties(foo PROPERTIES OUTPUT_NAME "foobar")</code> 
  will create <code>libfoobar.so</code>.</p>
  
  <p>How to change this behavior?</p>