[Gtk] on middle click, open all bookmarks in tabs
[Gtk] on middle click, open all bookmarks in tabs

When a subfolder (i.e. a folder in a dropdown menu, not on the bookmark bar itself) is middle clicked, it should open all sub nodes in tabs.

BUG=34416
TEST=none

Review URL: http://codereview.chromium.org/2968004

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@52123 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser