Optionally remember osc parameter values per osc type

[mkruselj]

So currently, when we load an oscillator type, we take a preset from configuration.xml. And this is fine and dandy for a very first load.

Perhaps having an option to remember last used oscillator settings per oscillator type might be useful to people, so let's jot it down here. Obviously, modulation should still be cleared when changing osc type, but the settings themselves (minus the octave/pitch/keytrack/retrigger) should stick around, in case this option existed and was enabled.

[mkruselj]

After further thought, I'm bailing out on this idea. Sounds like more trouble than worth.