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"

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

upd: optimization openocd version control

upd: optimization of openocd (mips) installation procedure

This reverts commit b04ddad1.

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)

This enables WDT, so sketches do not work.

Port of https://github.com/arduino/Arduino/pull/4737

Fix #124

See https://github.com/arduino/Arduino/pull/2175

Quoting the original commits from Matthijs Kooijman:

    Enable C++11 support

    This uses the gnu++11 standard, which is C++11 with GNU extensions.
    C++11 should be full compatible with the previously used C++98
    standards, so all pre-existing sketches should continue to work.

    Enable C11 support

    This uses the gnu11 standard, which is C11 with GNU extensions.
    Previously, gnu89 was being used, which is pretty ancient by now. C99
    brings some important improvements, some of which were already available
    and used even without this option. C11 is more recent and brings more
    minor improvements. Most notable feature is the static_assert statement,
    allowing checking invariants at compiletime using the full C
    expressions.