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

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.

Otherwise a compulsory property should be added to every board (3rd paty hell).
The bug is related with IDE's uploadUsingPreferences; the property map used to expand the receipe is derived from board properties and overwritten by the programmer's properties.
So no default can exist, and no global variable either.

Main differences:

* avrdude compatible vs bossac bootloader
* flash location of user sketch (0x2000 vs 0x4000)

Add method to automatically retrieve sketch start