begin moving image loading, which was previously handled by

the spritesheetmanager, and move this into the Image class.

this makes everything loads cleaner
add some image properties to Image class
separate bind and generate and loadimage within Image class

make spritesheetmanager begin using this class proper..
fix FTBFS
load spritesheets now, using the new loader
minor format
aaand we're back to normal, with the refactor of the texture handling

and image loading. feels nice :)

for some reason though, a 2nd glBindTexture is needed after the first,
and after glTexImage2D, otherwise it crashes on "invalid enumerate" for
the GL error log. why, i'm not sure...
rm 2nd texture bind, it works now..somehow.

i blame late night debugging.