Add USB test app.
Fix emulator target.

$? is the list of files that were modified since last build. $^ is the
list of all required files, which is what we need here.
Add simple (wrapping) mouse cursor
Convert to "simple mode" 0 (80x35 text)

* This removes the color gradient from the text.
* Makes the code slightly simpler.
* Remove various now unused files.
implement simple sampler

Simple sampler to use in games. This is basic since the test_sampler
does not use SDcard (to be tested & implemented).
Merge remote-tracking branch 'pulkomandy/master'