Proof-of-concept version of the RepRapFirmware make script
Multiple new features added

- Only compiles changed files for faster recompilation.
- Shows less output to keep the compilation result clean.
- Added command line parameter 'clean' to clean the project.
- Added command line parameter 'verbose' to show more output.
- Removed the (not so interesting) ELF file statistics table.
- First implementation of MacOS support, and it almost works.
Added command line parameter 'install' to upload the firmware
Make install works on MacOS with use of 'lsusb' script

Special thanks to jstck for helping me test this script!