thirdparty: Add submodules

Added submodules: avr-uip-2 and umqtt
src: Initial commit

Added source files.
utils: Add the tooled.groovy script

This script converts provided image to array of bytes suitable for sending to
the OLED display using functions specified in src/oled.h. The height of the
converted image does have to be divisible by 8.

Usage: ./tooled.groovy image1.png image2.png ...
utils/graphic: Add fonts

Added fonts and images to utils/graphic. These images can be converted to C
arrays using the tooled.groovy script.