Make findClosestLoadedTab aware of tab groups, and limit its search to
the currently active tab group. Should fix BitBucket issue #7.

This logic was originally developed for BarTab, and a more detailed
development history can be found at:

https://github.com/inverseparadox/BarTab/
Make unloadOtherTabs aware of tab groups, and provide an option for
whether its scope should extend to the entire window or just to the
currently active tab group, with the latter as default.

This patch was originally written for BarTab, and more detailed history
of its development can be found at:

https://github.com/inverseparadox/BarTab/

Unfortunately, in BarTab Lite X the "entire window" case is badly
buggy. It is therefore not recommended to change that option away from
its default, unless you want to work on fixing that bug.
Add myself to the list of contributors.

--HG--
extra : source : 9c58713cf6b66474597ec674c4b14e3446b262e9
Prepare 1.5 release