added a buffer clear before writing (com_clear())
Added Atmega324PA to bootloader device list
Changed Makefile to make ATmega324PA flash
Avoiding name conflict with CAL1

Changed CAL1, CAL2, RAW1, RAW2, M, B to cal1, cal2, raw1, raw2, cal_m,
cal_b.
CAL1 was conflicting with a symbol defined in ATmega324PA include, so
made everything else consistent with case change
updated readme to reflect ATmega324pa flashing
Added commented-out lines for deprecated atmega164pa
added removing elf to make clean
added removing binary in make clean
added pre-built hex for atmega164pa and atmega324pa