pcb: Added the pcb files
pcb: Fixed wrong value of the Ethernet termination resistors

Value was 49k9, corrected to 49.9
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.
src: Remove unnecesary file deletion in Makefile

As we are calling GCC only once, there are no intermediate files generated.
.gitignore: Added .map to .gitignore

.map is a file generated by the build process
src: Added sensors_send()

The sensors_send (and the sensors_send_* macros) contain common code which was
previously duplicated in the main function.
src/main.c: Moved weather parsing/displaying logic to new function

Previously, the parsing and displaying was done directly in the mqtt message
handler. This commit moves this part of the code to the newly created
display_weather function.
src/main.c: Remove extraneous call to display_therm()

For some reason, the display_therm function was called every time the
kalive_timer expired.
src: Make the temperature and humidity sensors optional

By defining HAS_DHT and/or HAS_DS in the config.h file, the firmware can be now
compiled without support for any of these sensors. This also stops posting the
sensor information to the corresponding MQTT topic.
src/common.h: Added common.h

common.h contains some miscelleneous preprocessor macros.
src: Added support for button inputs

This feature allows us to watch for falling edge on defined GPIO pins and report
this to the MQTT broker. The GPIO lines are software debounced and have the
internall pullups activated on startup.
src: Convert simple for loops to use the new times() macro
src: Disable IP packet reassembly

We do not need it and it saves around 300 bytes of RAM.
src: Moved subscribe calls to main.c
src/main.c: Added binary outputs

Pins declared as output set state to high/low on receiving MQTT message with
"true"/"false" as content on their respective topic.
src/main.c: Changed structure of sensor handling functions

This commit splits most of the sensor handling code to separate functions. This
makes the #ifdef-ed parts of the main function slightly more readable.
thirdparty/avr-uip-2: Update to upstream version