I downloaded and built the source code to add a few tweaks that I couldn't add with scripting.
Are questions about the source code allowed here?
Now 3 years later, see Source code questions in 2016
It was decided by the community (see #4) to make these off-topic for several reasons.
... Q&A site for people who use Blender to create 3D graphics, animations, or games.
So keep it to scripting only — Python, GLSL and OSL only related questions are allowed to an extent if kept minimal and in relation to Blender but for anything else programming related, you are better off asking on StackOverflow, the bf-committers mailing list or visiting the IRC channel
#blendercoders on the freenode network.