Move firmware to a subdirectory

firmware/Makefile

firmware/src/hcolor.h

firmware/src/main.cpp

firmware/teensy3/Arduino.h

firmware/teensy3/Client.h

firmware/teensy3/HardwareSerial.h

firmware/teensy3/HardwareSerial1.cpp

firmware/teensy3/HardwareSerial2.cpp

firmware/teensy3/HardwareSerial3.cpp

firmware/teensy3/IPAddress.cpp

firmware/teensy3/IPAddress.h

firmware/teensy3/IntervalTimer.cpp

firmware/teensy3/IntervalTimer.h

firmware/teensy3/OctoWS2811.cpp

firmware/teensy3/OctoWS2811.h

firmware/teensy3/Print.cpp

firmware/teensy3/Print.h

firmware/teensy3/Printable.h

firmware/teensy3/Server.h

firmware/teensy3/Stream.cpp