Added a menu item in Browser called Close other tabs

This closes all other tabs except the current one (only for the phone interface)
Will submit patch for tablet interface once this is approved.
It solves the problem of mass closing unneeded tabs to a certain extent.
Preferred method would be to select multiple tabs like list items.

Change-Id: I5af00f1c19043104987375f1da396eb6fefb5dd4
5 files changed