[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
 - [ardrone] added daren's mag freeze fix
[boards] lisa_m: AF remap for PWM using TIM3
 - [ardrone] daren's mag freeze fix, cleaned up acc. to suggestions
Merge branch 'master' of https://github.com/paparazzi/paparazzi into ardrone_mag_freeze
[rotorcraft] fix stabilization_attitude_ref_idx_set_omega_*
[rotorcraft] guidance_v: limit z_ref in update_ref_from_zd_sp

Limit the gv_z_ref to GUIDANCE_V_REF_MAX_Z_DIFF (default 2m) from current z position.
This should be useful if the aircraft can't follow the alitude in climb mode (e.g. when limited by max throttle).
[ground_segment] server: fix kml export
Merge pull request #767 from x75/ardrone_mag_freeze

[ardrone] added daren's mag freeze fix