add preliminary sun pos and time handling
add time class, to handle...time...

should automatically increment and rollover. it uses 12-hour based
time, even though i'd like to use 24-hour, it's probably more confusing
to do so ultimately.
time class should be "done", even has builtin formatting
return a uchar for time functions. underlying primitive is uchar anyways
excellent, now hooked the new time code into sky pos calc

going to have to tweak the angles, they're inverted it seems
++ sky tiles(empty beginning of tilemap)

, compensate to the correct quadrant (add 90 degrees) to our angle
do proper calculations, and for minutes as well

the matrix needs to be rotated counter clockwise a bit
use a 24 hr clock..way easier, this should be
make sun arc actually 180 degrees. needs compensation initially tho
more moon..but also less
back to rendering the sky at the bottom ;)
add colorscale class, a gradient class from some bloke's code

add Renderable::setUncachedTexture(), so that it is well known that
not using ::setTexture results in not using the image manager and its
ref counting
remove colorscale/grad..turns out that's as slow as i expected
add sky night,day and dusk images. they're pretty terrible
add crappy star_{normal,bright}.png
minor name change
Merge branch 'sky'

Conflicts:
	CMakeLists.txt
	src/image.h
	src/renderable.cpp
	src/sky.h
	src/world.cpp