Implement BTab scrollers

[cipri]

Sometimes, when there there are more tabs, and not much space, it becomes clear, that it would be better if the tabs would be more "intelligent" and adapt to space available instead of hiding the tabs. Perhaps tabs similar to the ones in google chrome would be more useful. The spacing is too much, when there is anyway not enough place for all tabs.

[cipri]

If you look at the screenshot at the tabview on the right side, you will see how much space is wasted. I guess the current tabs have a "minimal size" that is by far too big. Perhaps it should be set by default to a lower size?

[cipri]

I noticed now the existence of B_WIDTH_FROM_LABEL :P. It looks now better, but i wished I could be made even more compact. Perhaps something like an "B_WIDTH_COMPACT" could be introduced? And/Or and option which truncates the titles of the tabs if they are too long.

[cipri]

I propose to close it as invalid (since now it doesnt make anymore sense to me).