MRG: updating build script to latest versions

Python download link has changed.
No need for easy_install now get-pip.py is available.
Newest Python 2.7 is 2.7.6
dateutil now works on Python 3
Testing now on 10.9 not 10.8 (though this is just cosmetic).

Still failing when building against System python because of this bug:

http://stackoverflow.com/questions/22313407/clang-error-unknown-argument-mno-fused-madd-python-package-installation-fa