This enables remote wakeup on CDC driver, so we can safely call standby() and maintain the Serial prints on resume.

Correct OpenOCD version in tools.openocd.path definition

http://downloads.arduino.cc/packages/package_index.json specifies
openocd version 0.9.0-arduino6-static in the Arduino SAMD Boards 1.6.13
entry. The incorrect version previously used to define
tools.openocd.path caused uploads for SAMD boards to fail:
"java.io.IOException: Cannot run program
"{runtime.tools.openocd-0.9.0-arduino5-static.path}/bin/openocd.exe":
CreateProcess error=2, The system cannot find the file specified"

Add SDU usage example

Add support for updating sketches from an SD card

Fix #216

CMSIS-Atmel 4.5 changed the prescaler defines to match the bit mask, not the actual prescaler value, thus `SYSCTRL_OSC8M_PRESC_1_Val`  now means "divide by 2"

Fixes https://github.com/arduino/ArduinoCore-samd/issues/214

Via 2nd stage boot code that checks SD card for UPDATE.bin

Add virtual beginMulticast(...) stub to UDP class

https://github.com/arduino/ArduinoCore-samd/commit/5b7c293b2f9c86d1ef75708ba0ebc2755e5bd39b changed the dependency from CMSIS-Atmel 1.0.0 to 1.1.0

upd: optimization openocd version control

upd: optimization of openocd (mips) installation procedure

    * cores/arduino/wiring.c:

This reverts commit b04ddad1.

Set full PINCFG register on pinMode(pin, OUTPUT)

Fix #206

not working, disabling until we found the issue.