Fix cgit_parse_url when a repo url is contained in another repo url

For example, if I have two repos (remove-suffix is enabled):
  /foo
  /foo/bar

http://cgit/foo/bar/ is interpreted as "repository 'foo', command 'bar'"
instead of "repository 'foo/bar'"
git: update to 1.9.2

Everything works just bumping the version in Makefile and commit hash in
submodule. No code changes required.
footer: link back to cgit home page

The footer has always been overrideable using the footer= in cgitrc, so
this won't anger anybody who cares about their footer.
ZX2C4 specific patches.
Steal kernel.org's libravatar lua.