Gevent on OS X Raw

Saving [this](http://www.snip2code.com/Snippet/55467/How-I-installed-Bokeh-without-conda-on-O) here...

```bash
pip install bokeh # Fail
# gevent requires libevent, although you'd never know it from the error message  
brew install libevent  
      
# configure: error: C compiler cannot create executables ???  
# Update Command Line tools for XCode  
# No love  
# find this: http://stackoverflow.com/questions/13041525/osx-10-8-xcrun-no-such-file-or-directory
sudo mv  /usr/bin/xcrun /usr/bin/xcrun.bak  
sudo vim /usr/bin/xcrun  # Replace contents with #!/bin/bash $@   
sudo chmod +x  /usr/bin/xcrun  
   
pip install gevent # NOPE  
sudo ARCHFLAGS=-Wno-error=unused-command-line-argument-hard-error-in-future pip install bokeh  
   
# FINALLY IT WORKS
```