Refactor|Client|FontLineWrapping: Working on wrapping of tab stops

Previously GLTextComposer was solely responsible for tab stops,
however obviously the line has less room for text if tab stops are
being applied.

Refactoring FontLineWrapping so that it can check tab stop widths
already during the line wrapping process.
Fixed|Client|FontLineWrapping: Wrapping tabbed lines

Now the line wrapper correctly takes tab stops into account when
determining wrapped rich text lines.

Also added some more comments and cleaned up the code a little.