Turn off path quoting for git diffs.
Turn off path quoting for git diffs.

If a filename in a git diff uses complex unicode characters (such as CJK),
instead of including those characters in the diff header, the utf-8 encoded
bytes will be escaped using a \decimal syntax. This syntax is really difficult
to disentangle on the server side without writing our own parser. Luckily, it's
pretty easy to turn off this quoting.

Testing done:
Created a file called "中文\test" and ran `rbt diff` and `rbt post`. Saw that
the diff it was posting no longer included escaped bytes.

Fixes bug 3630.

Reviewed at https://reviews.reviewboard.org/r/6835/

reviewboard/rbtools,davidt/rbtools,beol/rbtools,haosdent/rbtools,beol/rbtools,davidt/rbtools,beol/rbtools,datjwu/rbtools,halvorlu/rbtools,haosdent/rbtools,haosdent/rbtools,datjwu/rbtools,halvorlu/rbtools,reviewboard/rbtools,datjwu/rbtools,davidt/rbtools,halvorlu/rbtools,reviewboard/rbtools