GR-1 Firmware 2.4.1

Bug fixes:

- Copying big samples (>=1 minute) caused undefined behavior (possible crashes, messed up sample buffers)!
- Range checks on many CC's to avoid crashes and undefined behavior.
- Audition mode: focussing on another part used to reset play position. Now it bravely plays on. 
- Inserting two of the same USB sticks -> only one showed up.  
- Killing a performance or preset now wipes the entire 112 seconds of buffer.
- LFO1,2 or CV1,2 Matrix settings sometimes lost when editing only a single destination in matrix mode. 
- Sub oscillator frequency pot setpoint was badly calculated.
- With 7 bit CC, tuning didn't exactly come all the way up to 2.0. 

Known issues:

- Clicks in distortion FX (similar to snare instrument pick up noise) when multiple voices triggering/releasing..
- No visual feedback on a bunch of CC's.
- Freeze on first USB plug after firmware update (a very old one).