Colours

[Kai Willadsen <kai willadsen gmail com>]

Hi all,

Current master now uses GTK's CSS provider for themeing. This may well
be quite broken, but since the gtkrc mechanism didn't work at all for
GTK 3, this is still an improvement.

The biggest user-visible change here is that the default colours have
changed slightly (they may change again, but this is the current best
effort version) and inline highlighting now no longer applies a text
colour to inline modified text; it is *background only*.

This change is because the visual appearance of the inline modified
blocks made the screen very visually noisy, and it could be difficult
to pick out actually important differences. It's also nicer to *only*
theme background colours, as this makes it somewhat easier to
integrate with syntax highlighting and alternative themes.

cheers,
Kai