New: added replaceTabsWithWindow method; overlayed context menu.
New: added multiselect support for reload, pin, unpin context menu items.
New: added multiselect support to "Close tab" item (removeTabs method).
New: override of removeAllTabsBut method to support multiselect.
README updated; new features.
New: panorama support.
Minor: added some comment to make clear what methods are overriden.
New: context menu items supporting multiselect are bold now, when relevant
Minor: dont make menuitems bold when only one tab is multiselected.
New: support for bookmarking all multiselected tabs via context menu.
Min supported version updated.
Fix: updating tab group menu items on popupshown instead of popupshowing.

Oncommand attribute of tab group menu items are updated to support
multiselect. Do this update when all menuitems were created, i.e. on
popupshown. Popupshowing is too early and we may miss some items to
update.