cogl/cogl-pango.h is deprecated. This also bumps up the Clutter
requirement to 1.8 which is where the header was introduced.

g_source_get_current_time is deprecated so it gives an annoying
warning. This changes it to use g_source_get_time with the monotonic
clock and gint64s instead of GTimeVal which also makes the code a lot
simpler.

The glib requirement has been bumped up to 2.28 to get the function.

Previously DFight was creating its own X window and passing it to
Clutter as a foreign stage because at the time Clutter's handling of
resizable stages that go fullscreen didn't work very well. It seems to
work fine now though so this patch just removes the whole thing.

Similar to 0b14e101cc, this makes the generate-piece-previews program
use Mash for the lighting instead of directly using GL.

This adds a one second timeout before rendering the piece previews to
give GL a chance to settle down.

This changes it to use float instead of GLfloat. Using GLfloat is
pointless and it relies on Cogl including the GL header for us which
it might not always do.

This changes DfightGame to use a MashLightSet instead of directly
using GL. This should make it more robust against changes in Cogl.

Querying a bit was broken for 64-bit architectures because the cast to
gulong was done on the result of the shift not before so it would end
up clamped to a 32-bit value. This was making the wrong piece
be highlighted when the lasers are fired.

The mask for clearing a bit was wrong because it was negated before
the shift not after so it would end up also resetting all bits lower
than num. This didn't cause any bugs because the only place it was
used checks for all of the bits in increasing order so the lower bits
would already all be cleared.

DfightGame used to have a mechanism to delay loading the game data
until it was needed. I think there used to be some reason why the data
would be unloaded but it doesn't look like this is neccessary
anymore. Instead the _init method loads the data and the _finalize
method destroys it.

clutter_x11_get_stage_visual is deprecated so it should use
clutter_x11_get_visual_info instead to get rid of the warning.