Get rid of Clutter.Actor.set_anchor_point_from_gravity call

This API is deprecated.
Updated Spanish translation
mapView: Don't use deprecated Clutter API

Although Champlain.View.bin_layout_add() doesn't come from Clutter but
it forces us to use deprecated Clutter.BinAlignment enum.

This also fixes the issue of reveal button appearing in the opposite end
of the map against Champlain git master.
Update libgd
Use an .ui file for the main window structure
Allow to create stateful actions
mapLocation: Wait for ensureVisible animation to complete

This fixes the weird glitch of map going to some random location. This
requires my patch to libchamplain:

https://bugzilla.gnome.org/show_bug.cgi?id=698213
mapLocation: Remove redudant workaround

With following patch merged to libchamplain, we won't need this
workaround:

https://bugzilla.gnome.org/show_bug.cgi?id=698213