bug fix, code cleanup, new defaults

- preparation for channel order definition on profile-level in config.h
- default expo values in profile 3 changed
- defaults for transmitter voltage warning levels changed, using cell
calculation now
- comments in the main t5x.ino cleaned up to match current
implementation in a better way
- g_PotiA6 renamed to g_Pot1
- moved InputToOutputPipe up to have a more logical order of definitions
- bug: we moved the poti to the inputToOutputPipe, but forgot to assing
input-system to the analog-pin constructor