[FR] Git blame support #650

Support viewing git blame information when browsing code. I personally like GitKraken's approach of putting the blame information inline with the cursor.

Getting blame data

Got a prototype working here. Basically, we can use git blame -w -M -C --line-porcelain -L <start_line>,<end_line> <filename> to get blame information for a given range within a file. We then parse that into a data-structure we want, expose it over a api, and bingu bangu.

Rendering blame data

I do like how GitKraken renders blame information inline.

On hover over, we get a ton of data:

• Author
• Date of commit
• GitHub issue / PR
• Removed and added line (diff)
• Commit SHA (hyperlinked)