[mcu_periph] gpio helper functions

also removed the old gpio1 that was used on lpc and fixedwing firmware
GLS (new)

implemented a new intercept that takes into account wind on final and APP_Angle
fixed desired altitude to match the actual setpoint
should work now with any type of vertical control since all control parameters have been removed

closes #453
[conf] fix some example GLS_APPROACH defines
[stm32] spektrum for F4

Not tested on an actual F4 board!
Using some of the new gpio helper functions.
Also removed seemingly useless DebugInit.
[stm32][i2c] pin configuration in board files

Use the gpio_enable_clock helper function.
Also remove the unused scl_pin and sda_pin variables in the i2c struct.
[conf][stm32] spektrum defines for Lisa/L
[stm32][conf] fix UART1_GPIO_RX on lisa/m
[stm32] i2c3 for stm32f4, untested
[stm32][ppm] config cleanup
[boards] add missing defines for lisa/l board
[rotorcraft] fix stabilization_attitude_read_rc_setpoint_eulers

Reported by Ewoud.
The constants max_phi_scale etc. were zero because it is an integer divide
where the denominator is larger (depending on STABILIZATION_ATTITUDE_SP_MAX_PHI).
This causes the euler setpoint to always be zero.

Closes #461
[peripherals][imu] i2c slaves for the mpu60x0

new IMU drivers using the mpu60x0 peripheral with slave support
- aspirin 2 (spi) driver with mag as real slave
- drotek 10dof v2 with mag as passthrough slave (untested and axes might be wrong)

closes #450
closes #190
[rotorcraft] rc euler read in fixed point

closes #462
[airframe] updating some ENAC airframes
[rotorcraft ]Added ardrone2 sdk version gps, fixed some bugs.

The GPS receiver from parrot is added for the SDK version of the ardrone2.
This new gps receiver is the flightrecorde from parrot.
Also fixed some bugs in the navdata receive of the SDK version, and added some comments to the INS.

Closes #463
cleanup some trailing whitespace
[rotorcraft] check_in_flight without RC

Closes #464
Changes to make ARDrone2 SDK fly without joystick
Still needs to be properly solved as per issue #201
[conf] update example sessions for ARDrone2

Removed Logitech Joystick because users are not going to have it and it will cause error messages when they launch it.
Adding notes in Wiki on how to add joystick yourself.
We now only need one session for ardrone2
[release] v5.0 stable version
Updated to newest locm3