Merge pull request #7727 from beduino-project/bluepill-rebased

boards/bluepill/Makefile

boards/bluepill/Makefile.dep

boards/bluepill/Makefile.features

boards/bluepill/Makefile.include

boards/bluepill/board.c

boards/bluepill/dist/openocd.cfg

boards/bluepill/include/board.h

boards/bluepill/include/gpio_params.h

boards/bluepill/include/periph_conf.h

cpu/stm32f1/include/cpu_conf.h

examples/dtls-echo/Makefile

examples/gnrc_border_router/Makefile

examples/javascript/Makefile

tests/gnrc_netif2/Makefile

tests/thread_cooperation/Makefile

tests/unittests/Makefile