app_server::Transforable: Cleanup

 * No need to implement operator== and !=
 * Fix operator=() to be efficent, declare agg::trans_affine version, too.
app_server: Fix computing bounding boxes for transformed stuff.

 * In DrawingEngine, clipping is computed before drawing happens. This did not
   take into account when drawing primitives can now be transformed. Fixes
   drawing glitches in the Transformation test when the round rect is scrolled
   into view and it was previously prevented to draw.
 * Fixed clipping rect computation for the sanitized StrokeRoundRect()
   implementation which centers the stroke on the rect.
Updated.
app_server: Cleanup of some file locations