* Add support for .diff and .patch
Add the ability to get text-diff and format-patch by adding .diff or
.patch in the end of a commit url. Issue #2641
* models: git_diff: various fixes
* Renames commitId to commitID.
* Writes stderr to a bytes.Buffer and displays proper error message on
command failure.
* Various style changes.
Signed-off-by: Dennis Chen <barracks510@gmail.com>
dfab54d5a2