libgui|Font|RichFormat: Added escape sequences for tab positions

These will be used for aligning text on a line.
Client|FontLineWrapping: Cleanup
Console: Styled output for the "version" command

Todo for later: Using the style escape sequences this way is a bit
cumbersome. A more user-friendly HTML-like markup would be easier to
use, although it would require first parsing the markup into style
escape codes before entering into the log.
Merge branch 'master' of ssh://github.com/skyjake/Doomsday-Engine