Merge pull request #8 from cano64/master

Added support for 1Mhz, 8Mhz and 16Mhz frequencies for ATTiny85, ATTiny84 and ATmega328
first attempt
added comments on the atmega 8 changes
Merge pull request #11 from bredita/master

Add support for Atmega8
ATMega8 fix + 1Mhz support