Added 'Other Devices' menu

I added an 'Other Devices' menu containing the open tabs on other devices.
The implementation requires chrome build 35.0.1916.6 or higher, on builds before that the menu is hidden.

Localization of the "Other Devices" text needs to be added for all languages except for EN and NL
Optinally, the timeago script should be localized for any language that is not yet in the js/timeago/locales folder