Reset the SAM3X8E before flashing
so as to avoid some hangups in the flashing process
Reset udoo's MCU before flashing
Merge pull request #1380 from rousselk/arduino-due-minor-fixes

Reset ARM Cortex-M3 MCUs before flashing
board - arduino-due: some cleanup

- added parenthesis for LED macros
- changed mapping for LED_* to LED_RED_*
- removed some old values from periph_conf.h
board/udoo: cleanup in periph_conf.h

- removed unused defines