ide-1.6.x-R1.3.0

Changes to configuration fuses for all supported chips and fixes for ATmega8:

• Don't reserve bootloader memory to actually make all flash available to sketches;
• Fix upload failures for ATmega8 due to unsupported efuse parameter;
• Match ATmega8 fuse configuration to the other supported chips:
  • enable brown-out detection at 2.7V;
  • erase EEPROM on upload;
• Add external 8 and 12 MHz clocks to ATmega8.

Thanks to Atmel for providing me with ATmega8/168p/328 samples to test this configuration.