Add support for Arduino Leonardo.
Fixing (let)
Merge branch 'leonardo' of github.com:technomancy/microscheme into technomancy-leonardo

Conflicts:
	src/lexer.c
Merge branch 'technomancy-leonardo'
Changing port mappings for leonardo
minor
Adding support for hexadecimal literals
Adding binary literal support
Fixing leonardo port mappings
typo
Fixing Leo header file
Starting to clean up examples
Re-writing port mappings in hex (to match datasheets better)
Adding a nice marquee (scrolling message) example...