include stdio for printf, remove unused variable warning
try to work around some versions of gcc not liking duplicate members in anonymous structs
reduce occurence of printf, reduce binary size
WDT reset triggers DFU mode
use LEDs to show DFU download progress
slightly reduce debug output
main: ensure smoothieboard heaters are turned off
Makefile: rebuild if Makefile changes
handle watchdog better
bump version
Merge branch 'release/0.3'