Implement min/max values in Blofeld param list and make info available to UI

* I.e. Blofeld module gets UI values (e.g. Bend range -24..+24), and
  converts them to MIDI values.
* UI setup includes fetching min/max values from Blofeld and setting
  corresponding properties in gtk adjustments.
* Change name of UI file to blofeld.glade .
* Rudimentary UI, only implements Osc 1 for now.
* By default, use blofeld.glade as UI file, but also accept override from
  command line.
* Also added support for check and toggle boxes, such as Limit WT.
Always set adjustment values, so they don't need to be set in UI file
Use step size 2 for large-range parameters, i.e. keytrack
Added frame shadow to UI
Added osc 1 mixer

* Also renamed corresponding parameters, removing "Mixer" in name
Fix range for filter pan and osc 3 waveshape
Added Filter 1, plus mod names and osc waveshapes
Fix tab names, add another tab, added edit buf combo box and fetch button
1->3 oscillators, 1->2 filters, not tested on Blofeld yet
Fixed filter 2 type and cutoff names
Added filter env and env vel amounts to filter 1 and 2
Added Effect, LFO and Env parameters to parameter list
Added filter and amp envelopes to UI
Restructured layout, to put all mixer controls in one column

* Also added Osc common and Amplifier fields in order to verify final layout.
* Changed Height Requests from 80 to 78 to fit it all on screen.
* Disabled fetch and edit buf combobox to fit it all on screen.
Added bitmapped parameters, definitions and init only, no processing so far
Added filter routing parameter to UI
Implement bit map parameter update from UI to Blofeld
Implement bit map parameter update from Blofeld to UI

* Also fix missing handling of toggle button updates when updating from MIDI.
Use gtk_toggle_button_get_active instead of g_object_get(..,"active",..)
Implement receive of single edit buffer parameter dump; fix bipolar parameters