Add automatic build dependency generation

Add automatic generation of build dependencies for build targets. Slim down the
includes to only pull in what is actually used in the different C-files.
Merge pull request #8 from abbeman/master

Add automatic build dependency generation
added avr-size command to show the size of the generated .elf and know the free ROM RAM and EEPROM
Merge pull request #10 from jim17/master

added avr-size command to show the size of the generated .elf
Merge remote-tracking branch 'upstream/master'
Update to latest limpkin repo.