add tracking of seconds since last update cycle
reindent
AVR: add avrdude flashing to build system
BUILD: fix issues with more than one AVR module in the build
AVR: fix atmegsX8 uart support
add owslave library functionality
AVR: convert old owslave program to use new library
AVR: add owdio board firmware
create libmcp so multiple targets can use the code
BUILD: fix avr optimization
add support for multi bus UsbDongle
Add multibus owtempctl
AVR: improve owslave USEC calc

This improves the calc when FOSC is not an even multiple of 1MHz
AVR: add build support for atmega238p and atmega2560
AVR: add owrelay firmware
AVR: add ow firmware test for arduino uno
AVR: update default addresses for owrelay and owdio
AVR: read support to owslave

also start transition of dio from output only to PWM out + input