Add out of range test for tone

Note 71 of the percussion of bank 31 was crashing the synth.
An integer overflow combined with exponentiation resulted in such a large
value that it is regarded as infinite. Code flow was stuck in
the hz() loop to determine the octave.
Add appropriate range checks to avoid this in the future.
Fix number of lines in UI::PrintLn
Only show portamento warning if !=0

This avoids a flood of warnings when resetting controllers.