Tabpane now looking fine

I fixed the bugs in tabpane (posted in the sampler 0.5pre2 release notes)
with the exception of the unimplemented features (coming over the next
couple of days) and the 'artifacts' which I'm 99.99% certain are a core
issue.

The 0.5 release will be a fully usable widget set which I hope people will
use instead of the old widgets.

0.5pre3 (coming at the end of this week / start of next week) should fix
most outstanding bugs / unimplemented features planned for 0.5 and 0.5
should contain fully documented, usable widgets.

- Charlie

The future of webapps - www.xwt.org