Add pygments parser option

global now builds a pygments parser by default. Make this work with a --with-pygments option to the recipe.
TBH, I can't figure out what to do given gdal.rb. It's not obvious to me what it's doing with a python script by looking at the formula.

Basically global does this:

Substitutes #!@PYTHON@ in pygments_parser.py.in
Installs pygments_parser.py in {prefix}/share/gtags/script/pygments_parser.py
Compiles pygments_parser.c (which fork/exec's the above script) into pygments-parser.la.
Installs pygments-parser.la into {prefix}/lib/gtags/pygments-parser.la
dynamically loads pygments-parser.la from gtags to parse various (many!) languages

More guidance appreciated.

Thanks,
Chris.

On Sep 8, 2014, at 12:31 PM, Mike McQuaid <notifications@github.com> wrote:
> 
> gdal is a better example in that case. We'll need to fix this so it works similarly.