[stm32] add support of pwm_input for stm32

- two pwm input can be configured
- only TIM 1, 2 and 3 are implemented
- example in apogee board file
brackets for some macros
[stm32][i2c] use rcc_periph_reset_pulse instead of i2c_reset

i2c_reset is not implemented for I2C3 and rcc_periph_reset_pulse is the newer libopencm3 style.
closes #751
[navstik] Fix tests for the NavStik board

closes #752
[stm32] actuators_pwm: replace set_servo_gpio with gpio_setup_pin_af

- AFIO remap in board file
- gpio_setup_pin_af with uint32_t for af
- remove PWM_SERVO_x_RCC

closes #757
[peripherals] ms5611: check temp and pressure range

Discard measurement if it is not in valid range...
Based on proposal by Kevin, thanks!
[ardrone2] add generic upload/download functions

- make it easier to get or push files to the ardrone
- change upload_paparazzi function to a more generic name
Merge pull request #758 from paparazzi/ms5611_bounds

[peripherals] ms5611: check temp and pressure range
[stm32] i2c: fix reset

should be RST_I2Cx instead of RCC_I2Cx
was wrong in libopencm3 docs
[pwm_meas] use enum for pwm_in channel number
[module] add a new meteo module to get data from Meteo France PTU board
[modules] use VPATH to make it easier to load external modules
[electrical] fix for negative currents

this should fix #753
[ins] allow define of VFF_R_SONAR_OF_M

closes #764
[meteo] update doc for mf_ptu module, log field names and units