Initial blame API
Change API based on @arrbee's feedback
Introduce git_blame_buffer
Fix spelling, remove pesky consts
Blame: alloc/free scaffolding
git_blame_results -> git_blame
Adjust naming, signatures slightly
Add blame test repo
Add more test skeletons, binary search for hunks
Fix msvc build
Add revwalk skeleton
Some work on trivial blame
Count lines in blob
Some progress toward trivial blame