title: Can't install pylibmc by pip
body: <p>I'm trying to install pylibmc on mac.<br>
  mac env is osx el capitan 10.11.2.</p>
  
  <p>I tried <code>pip install pylibmc</code>. but I received following error.  </p>
  
  <p>I already installed list below.  </p>
  
  <ul>
  <li>brew install libmemcached</li>
  <li>Command Line Tools</li>
  <li>export CFLAGS=-Qunused-arguments  @shell</li>
  <li>export CPPFLAGS=-Qunused-arguments  @shell</li>
  </ul>
  
  <p>How can I install pylibmc??</p>
  
  <pre><code>Installing collected packages: pylibmc
  Running setup.py install for pylibmc
  Complete output from command /Users/username/.virtualenvs/django-proj/bin/python2.7 -c "import setuptools, tokenize;__file__='/private/tmp/pip-build-goDKgm/pylibmc/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-wxC5F1-record/install-record.txt --single-version-externally-managed --compile --install-headers /Users/username/.virtualenvs/django-proj/bin/../include/site/python2.7/pylibmc:
  running install
  running build
  running build_py
  creating build
  creating build/lib.macosx-10.11-x86_64-2.7
  creating build/lib.macosx-10.11-x86_64-2.7/pylibmc
  copying pylibmc/__init__.py -&gt; build/lib.macosx-10.11-x86_64-2.7/pylibmc
  copying pylibmc/__main__.py -&gt; build/lib.macosx-10.11-x86_64-2.7/pylibmc
  copying pylibmc/client.py -&gt; build/lib.macosx-10.11-x86_64-2.7/pylibmc
  copying pylibmc/consts.py -&gt; build/lib.macosx-10.11-x86_64-2.7/pylibmc
  copying pylibmc/pools.py -&gt; build/lib.macosx-10.11-x86_64-2.7/pylibmc
  copying pylibmc/test.py -&gt; build/lib.macosx-10.11-x86_64-2.7/pylibmc
  running build_ext
  building '_pylibmc' extension
  creating build/temp.macosx-10.11-x86_64-2.7
  clang -fno-strict-aliasing -fno-common -dynamic -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/System/Library/Frameworks/Tk.framework/Versions/8.5/Headers -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -DUSE_ZLIB -I/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c _pylibmcmodule.c -o build/temp.macosx-10.11-x86_64-2.7/_pylibmcmodule.o -fno-strict-aliasing
  In file included from _pylibmcmodule.c:34:
  ./_pylibmcmodule.h:42:10: fatal error: 'libmemcached/memcached.h' file not found
  #include &lt;libmemcached/memcached.h&gt;
           ^
  1 error generated.
  error: command 'clang' failed with exit status 1
  </code></pre>