Configurable knobs-grab-focus in popup menu (by default enabled)
Minor cleanup in blofeld_knobs.c
Synced som parameter names with frame names

* Mostly in Osc Common frame.
* Also Ring frame -> Ringmod frame to be consistent with param names
Add type parameter to controller notify callback
Some renames in preparation for button maps
Add support for buttons in addition to pots/incrementors

* Also fixed bug in controller_change() where accelleration was not
  implemented for other than the Speed Dial.