[kuroneko] improved TextBox method

re: [0] vs {0}
In SPIN accessing value[0] is the same as value, the latter is smaller
and faster. To keep the idea of an array access we use comment brackets
which look like an array access but don't cause the overhead.
[kuroneko] multiply op is fast enough to be used
[kuroneko] sprite renderer, WIP
[kuroneko] note re: multiply, x8bit with early exit may be enough
[kuroneko] sprite renderer, WIP
[kuroneko] whitespace changes
[kuroneko] clearscreen now blit(0)
[lamestation] Modified LameFunctions Sleep to use waitcnt-based timing; updated all demo with Sleep; switch TankBattle to external graphics files
Merge git://github.com/konimaru/lamestation-sdk
Forgot one image file