Proposed changes to add format change functionality

[berbaba]

• There might be a better/more elegant way for choosing the output format than the global variable format_mm.
• Not sure if it is needed to save changes with sendCommand( SAVE_SETTINGS,0) if the format is changed or it's not necessary at all. Could be removed or put inside the if(format_mm==true) after sending the command with STANDARD_FORMAT_MM.
• Changed the comments at the beginning to match the new line numbers due to the added lines.