Updated German translation
dateMenu: Don't generate JS garbage every clock tick

Instead of waking up the JS every second to set the clock and update a
date label the user will rarely see, simply use property binding to
bypass JS string handling, and update the date in the menu when the menu
is opened.
Updated Chinese (Taiwan) translation
screencast: Properly stop all recordings on session mode changes

We currently just clear out the map of recorders (which results
in the top bar indicator to be hidden), but don't stop the actual
recordings.
Spotted by Adel Gadllah on IRC.
shell-screenshot: Only allow one screenshot request at a time per sender

We currently allow infinite number of screenshot requests to be active at
the same time, which can "dos" the system and cause OOM.

So fail subsequent requests for the same sender when a screenshot operation
is already running.

https://bugzilla.gnome.org/show_bug.cgi?id=737456
theme: top bar styling.
theme: overview search bar styling