Add a background color and scroll overflow.

Set a max width of 1000px and make some spacing and sizing changes.

This just adds a rule for cgit.css.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Update to git version v2.54.0, this requires changes for these
upstream commits:

* d9ecf268ef3f69130fa269012318470d908978f6
  odb: embed base source in the "files" backend

* cb506a8a69c953f7b87bb3ae099e0bed8218d3ab
  odb: introduce "files" source

... and probably more related.

Signed-off-by: Christian Hesse <mail@eworm.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

These would be largely invalid anyway (save, I suppose, for Linux file
paths that technically can contain new lines).

The actual problem is that these get printed back out into cached -- and
trusted -- cgitrc files, and if the fields have newlines, the git-config
way of less trusted users configuring repos on a shared system can be
abused to inject newlines, which then can be used to smuggle global
options (including filters, which execute code) into the cached cgitrc.

So now, only ever duplicate up to the newline, when dealing with these
inputs.

Reported-by: Adrian Denkiewicz <adrian@doyensec.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>