add per commit parsing

[Mr-Bossman]

when looking at stats from a fork it may be important to only look at the commits the user does, not the repo as a whole. implement per commit language parsing by using git log --author=... and git format-patch

[samiam2013]

~cloc doesn't even know how to observe .gitignore afaik so what's the point of this~

[samiam2013]

https://stackoverflow.com/a/26679008 🙄