Add rhythms toolbar.

Image files taken from TamTamMini.
Toolbar-drums is a lighter shade of the tamtamMini icon.
Revert changes to the piano layout.
Fix pickupNewBeat error.
Add new svg beat icons.
Add new svg beat complexity icons.
Add new svg drumkit icons.
Make the drumkit icons white.
pep8 fixes.
Try to use sugar tooltips instead of Gtk3 ones. (WIP)
Tooltips don't work as of now.
Tooltip fixes. [WIP]
Finish adding sugar's tooltips.
pep8 fixes.
Reduce down the possible values for beat complexity and tempo for better UI.
Use the standard play/stop button.
Merge branch 'rhy' of https://github.com/lionaneesh/music-keyboard-activity into rhy

Conflicts:
	activity.py