Port to Teensy3.0 (ARM Cortex-m4 mk20dx128)
mk20dx128.ld: attempt to add .eeprom section
merge with Triffid/Teacup_Firmware/Gen7
README: add note on teensy3.0 development branch
README, Makefile-teensy3: Note differences for ARM compilation
Clean out some compiler warnings
Makefile-teensy3: clean up spurious generation of .d files
mendel.c,arduino_teensy3.h,analog_ARM.c: Enable ADC interrupt service
heater.c: enable PWM on pwm pins
heater.c: expand 8-bit PWM value to full range of PWM
README: Note that ADC+PID+PWM now works
config.teensy3.h: Add breadboard test circuitry notes for 3.3V interfacing
README: Note that EECONFIG and USE_INTERNAL_PULLUPS need work.