Fix marshalling of RGBA8888 value.

The problem with using Word32 is that it ends up in _native_ endian
format, which for this pixel format is a bit unsuitable because it's
actually a 4x8 bit byte array rather than a uint32_t.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
UI.Sprite: Prepare for nested sprites.

The reason I'm doing this at the most nested part is that we can
recursively emit subsprite data and afterwards we can flatten the whole
data in one go. One advantage of this approach is that it is easy to
add constructors for functions, so that we can render sprites
dynamically based on the function application.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
UI.Sprite: Use Data.Matrix for texture generation.

We're going to nest those data very soon, so we need ta have a sane
matrix implementation. And my intention was to switch to using
Data.Matrix (from the matrix package) anyway sooner or later, I guess
it's better to do it sooner. Also known as: "now" :-)

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Remove Python-specific .gitignore altogether.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
UI.Sprite: Reorder types on importance.

No changes in functionality.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>