Fix active sub-menus which didn't disappear when hover changes

Signed-off-by: Martin Koistinen <mkoistinen@gmail.com>
Updated Twitter plugin docs.

With links to possible alternate plugins from release notes.
Merge pull request #2559 from dteklavya/patch-1

Updated Twitter plugin docs.
Merge pull request #2557 from mkoistinen/toolbar-js-fix

Fix active sub-menus which didn't disappear when hover changes