Added a little instruction for OSX users for successful compiling on 10.8.5

swapping out `virtualenv env` for `virtualenv -p python2.7 env`
Updated docs to reflect MacOS instructions for getting started
Added some more file to ignore, such as the _build folder in docs and nasty .DS_store files on Mac
Merge pull request #42 from luzpaz/patch-1

Added a little instruction for OSX users
Merge pull request #44 from jvasallo/master

Updated docs to reflect MacOS instructions for getting started