some bug corrections
- fixed a bug that the spurious carrier burst was not suppressed in SPLIT mode
- In semiQSK mode, the initial CW element is now delayed by 65ms (to prevent the carrier burst), instead of canceled
- fixed a bug that the radio did not reliably switch from LSB to CWL in semiQSK mode
- fixed a bug that the display got messed up when the VFO is above 10 MHz