Create initial formula for installing kicad

Kicad does not release source code packages so this formula fetches
from the bazar repository which is unfortunately quite slow.  There
are three versions to get.  The normal url is the testing bazar
repository with the fixed revision this formula was tested at.
Unfortunately using the stable repository (commented out but
left in the formula) does not compile.  Head is the testing
repository head and using --devel enables the DKICAD_TESTING_VERSION
flag.  I also left the url to my github mirror for people that
want to fetch the code 100x faster.

Patches applied:
1) Required a patch since for some reason kicad disables the aui
module for wxWidgets which is required for compilation.
2) A second patch enable retina display on kicad

The caveat with location to app bundles like macvim.
Make sure that during devel version it takes from the testing branch
and passes the -DKICAD_TESTING_VERSION flag

Uses inreplace to set the share path to /usr/local/share instead of
the default for OSX /Library/Application Support