[settings] fix GCS settings page when only one mode in a process

This solves the case where a process as only one mode by removing the
corresponding setting (since there is nothing to change) and by removing
the complete telemetry page if no more process.
The case without modes in a process fails at code generation since at
least one mode is required.

fix #553
[conf] remove obsolete RC_CLIMB_COEF and RC_CLIMB_DEAD_BAND
[rotorcraft][guidance_h] GUIDANCE_H_USE_SPEED_REF defaults to TRUE

This also allows to give velocity commands via RC in GUIDANCE_H_MODE_HOVER.
[fix] fix mpl3115 driver and apogee baro_board
[fix] if no baro and no kalman, get vz from gps
[state interface] fix stateCalcHorizontalSpeedNorm_i
[crrcsim] use crrcsim as fdm with nps

Install the patched version of crrcsim:
https://github.com/paparazzi/crrcsim-pprz
Select MNAV as input of crrcsim
Run nps simulator with crrcsim fdm type
[ground_segment] one warning per line

for values not setable form GCS strip
[crrcsim] fix crrcsim/nps for 64bit computers
[crrcsim] fix udp sending compatibility with OSX
[nps] fix number of actuator commands used

This makes it finally possible to have e.g. a hexarotor:
Six "commands" (one per motor) from motor_mixing sent to the FDM.
[ground_segment] sane error when launching settings without specifying aircraft
[ground_segment] python settingsapp: no default ac ids
[uart] fix name for parity value
ignore .idea dir from JetBrains IDEs
[boards] stm32f4_discovery: fix/switch LED 3 and 4

to match board doc and silkscreen
[conf][nps] same simple_quad JSBSim model for most quadrotors
[ahrs] gx3 minor fixes

closes #565
[stabilization] float_euler fixes so it actually compiles
[rotorcraft] quat_float: rename x_sum_err_eulers to x_sum_err