pyterm: make pin toggling optional

For the MSB-A2 the DTR and RTS pins have to be pulled down over the
serial interface in the beginning. (This is required because the Linux
usbserial driver pulls them up when initializing the device which set
the node into reset mode.) Since this is not necessary on most other
platforms and might even cause problems, it's better to make this an
optional behavior of pyterm.
Merge pull request #1702 from OlegHahm/pyterm_dtr_option

pyterm: make pin toggling optional
cpu/stm32f4: fixed doxygen
Merge pull request #1705 from haukepetersen/fix_stm32f4_pwmdoxygen

cpu/stm32f4: fixed doxygen for PWM driver
cpu/sam3x8e bug: missing break statements in gpio_set() and gpio_clear()
tests/bloom: Prevent word lists from being copied into RAM.
tests/bloom: Un-blacklist boards mbed_lpc1768, stm32f3discovery, pca10000, pca10005, and yunjia-nrf51822.
Wake-up Travis
Merge pull request #1707 from locicontrols/bloom

tests/bloom: Prevent word lists from being copied into RAM and un-blacklist some boards.
Add license statement to {msp430_types,net_help}.h
Merge pull request #1700 from Kijewski/license-statement

Add license statement to {msp430_types,net_help}.h
Merge pull request #1706 from locicontrols/sam3x8e-break

cpu/sam3x8e bug: missing break statements in gpio_set() and gpio_clear()
drivers: import PIR motion sensor driver