Move selection of instrument to the toolbar

Replace the current instrument selection iconview with a palette.
Use svg icons instead of the png.

Signed-off-by: Aneesh Dogra <lionaneesh@gmail.com>
Reviewed-by: Gonzalo Odiard <godiard@sugarlabs.org>
Pep8 fixes on draw_piano.py
Set style on toolbar to BOTH_HORIZ

This is needed on sugar < 0.102 to display the instrument name
Merge branch 'latest_remote' into rythms

Conflicts:
	activity.py