- Improved machine status display (now it updates on the same line!)
   - Fix pending: see what happens in 'DEBUG' verbose mode
- Created sendGCodeInitSequence()
- Enhanced logging
- Stripped serial commands
- No need to add '\n' to commands in sendSerialCommand()
- Skipping unnecessary moves
- Added "Unknown command" for unknown keystrokes in verbose mode different than 'DEBUG'
- Rearranged code
- Added header comment
- Minor logging changes
- sendSerialCommand() / readSerialResponse():
   Added the option of specifying expectedLines=None and passing
   a new responseTimeout param to decide how much to wait for
   the response (used in showHelp() and direct gCode command sending)
- Logging changes
- Modified how absolute and relative coordinates are checked
- Rearranged available options (old code kept in comments for later use)