proper round corners on focused TextEntry

IFF [xy]thickness is set > 2 for given Entry.

It seems gtk draws a base-color rectangle on
top, after clearlooks_draw_entry() is called.
This fills the complete area and voids previous
rounded rectangles in clearlooks_draw_entry().
setting [xy]thickness decreases the size of the
base rectangle.
right side track-header control buttons (for non mixbus profile)
move midi scroomer to right of meter and fix alignment