Merge pull request #24 from sealibora/master

cores: Added atmega32
fifo: Updated to latest version

This version was lagging quite a bit; this one has memory barriers, and
an updated write()

Signed-off-by: Michel Pollet <buserror@gmail.com>
cores: Add porta to atmega32.


Also separate atmega8.h header from atmegax.h

--HG--
rename : simavr/cores/sim_megax.h => simavr/cores/sim_mega8.h