update compiler

[nerdralph]

gcc 4.7.3 is pretty dated. The latest AVR toolchain from Atmel includes gcc 4.9.2
http://www.atmel.com/tools/ATMELAVRTOOLCHAINFORWINDOWS.aspx

avr-gcc 4.9.2 and enabling lto (add -flto to the flags in cores/AVR8bit/makefile) should make a significant reduction in code size.
http://nerdralph.blogspot.ca/2014/04/gcc-link-time-optimization-can-fix-bad.html

[dbarragan]

thanks, we will look into that : )

[nerdralph]

It's issue #42. That muat be a sign that it is the answer to life, the universe, and everything! :-)