Require GTK+ 3.13.2

For RTL icon theme support
Rely on RTL icon theme support
Updated Swedish translation
Reword the error message for engine errors

It's been reported that the existing error messages could be confusing
to users. In particular, the notion of a computer program dying (error
message when the engine process is killed) could be confusing. Reword to
avoid this.
Rephrase the player death message

For whatever reason, PGN has a notion of player death, to be used if the
moons align and a player is unable to complete a game because he died.
Probably no gnome-chess user will ever see this message ever -- he would
have to load a specially-prepared PGN -- but let's make it less
confusing anyway.

https://bugzilla.gnome.org/show_bug.cgi?id=726454
Updated Hebrew translation
timer: use LTR character and mark for translation
Updated Lithuanian translation
Do not use Gtk.Widget.double_buffered

It no longer does anything. Le sigh.
Workaround signal misfires that led to crash

Even though the original ChessGame is always destroyed immediately after
the creation of a new one (no other reference to it exists), the signals
we connected to the original game may be nonetheless fired by the NEW
game object. This must be a bug in Vala signals.

https://bugzilla.gnome.org/show_bug.cgi?id=732067
style: remove aggressive line breaks
Revert "Workaround signal misfires that led to crash"

This reverts commit a3f1007fe7ea7270c188798e61cd4b7e7c00190e.
Better workaround for signal misfires
Don't create new fundamental types
Always enable New Game on game over

If something goes wrong with the engine before the first move, then the
user needs to be able to press New Game.
Update header bar title in game_undo_cb

Makes no difference, but this is where we handle the rest of the UI
Depend on GLib 2.40

For g_application_handle_local_options()
Start up GApplication-style

* Create the window in activate(), not startup()
* Override the handle_local_options() signal
* Override the open() signal
Remove references to a "2D/3D chess game"

Might not be 3D for much longer, and 3D is no longer an awesome feature
so there's no point in advertising it.
Rename gschema file

It's a little mean to reset users' settings, but I dislike the current
redundant name more strongly than I probably should. And only a little.

Also, fix i18n of the gschema