Merge branch 'zero' of github.com:aethaniel/ArduinoZero into zero

cores/arduino/Arduino.h

cores/arduino/IPAddress.h

cores/arduino/RingBuffer.cpp

cores/arduino/delay.c

cores/arduino/delay.h

cores/arduino/startup.c

cores/arduino/syscalls.c

...duino/validation/build_gcc/debug_arduino_zero/IPAddress.o

...s/arduino/validation/build_gcc/debug_arduino_zero/Print.o

...s/arduino/validation/build_gcc/debug_arduino_zero/Reset.o

...uino/validation/build_gcc/debug_arduino_zero/RingBuffer.o

...s/arduino/validation/build_gcc/debug_arduino_zero/delay.o

...s/arduino/validation/build_gcc/debug_arduino_zero/hooks.o

cores/arduino/validation/build_gcc/debug_arduino_zero/itoa.o

cores/arduino/validation/build_gcc/debug_arduino_zero/main.o

...arduino/validation/build_gcc/debug_arduino_zero/startup.o

...rduino/validation/build_gcc/debug_arduino_zero/syscalls.o

cores/arduino/validation/build_gcc/debug_arduino_zero/test.o

.../arduino/validation/build_gcc/debug_arduino_zero/wiring.o

...no/validation/build_gcc/debug_arduino_zero/wiring_shift.o