Merge Custom Buttons v. 0.1.0a1 - 2011-07-20
(aka Merge Buttons, see https://forum.mozilla-russia.org/viewtopic.php?pid=506131#p506131)
Get buttons only once, v. 0.1.0a2 - 2011-07-20
Wait for buttons initialization and try correctly close menus after click, v. 0.1.0a3 - 2011-07-20
Rewrite, v. 0.1.0a4 - 2013-02-06
Changed the main idea: now will merged all buttons/separators after this button.
And you can use two separators as "stop" flag.
Also refactored some code.
Better handle buttons with initialization, v. 0.1.0a5 - 2013-02-06
Drawback: we should reinitialize all buttons after each merge/split action.
This is not fast and no API for this, so we work with raw nodes and attributes...
+ Correctly close menus on mouse out
+ closeMenus() for Thunderbird
Add icon (from Fogue iconset):
http://findicons.com/icon/117070/ui_menu_blue?id=120165
Install page for v. 0.1.0a5 - 2013-02-06
Add description for Merge Custom Buttons