Squashed commit of the following:

commit 559841d6d75eaa2a4cc2d828375531c5a58ecfdb
Author: Br. Elijah Schwab, O.Carm <elijahschwab@gmail.com>
Date:   Tue Dec 23 10:49:11 2014 -0600

    Fix portability issue with python.

      - Change the python commands to explicitly call python2.

commit 600cd096676fd454e6d2efd9eaa4da1e1c45c7b4
Author: Br. Elijah Schwab, O.Carm <elijahschwab@gmail.com>
Date:   Tue Dec 23 10:38:31 2014 -0600

    Create Archlinux PKGBUILD for gregorio-git

      - Remove old PKGBUILD for gregorio-svn