... and add translator comments explainings what they do. The RTL
languages are likely going to want to show them in a different order.
We should eventually move to just using GnomeWallClock and/or
g_date_time_format with %c that already have translated the time format
strings. However, in case this doesn't make it in time for 3.10, mark
the current strings in g-c-c as translatable to get some translation
coverage.
https://bugzilla.gnome.org/show_bug.cgi?id=694985