AttitudeSettings: parameters for vertical complementary filter
Attitude: Altitude filter with normal complementary filter

This is work to separate the altitude estimation from the Altitude
controller. To do this we must always estimate the altitude in both
the complementary and INS filters.
Attitude: calculate the NED accel in the state estimation

This should always be computed since the altitude controller
uses it.
Attitude: set the values from the altitude filter

This is used when in "Raw" mode for the Navigation filter and
populates the vertical information.
Attitude: return the information fix
Attitude: altitude filter requires the NED z component
Attitude: allow configuring the time constant
AltitudeHold: strip this module to only the controller component

The attitude estimation from the baro and accel has been moved to
the attitude module so the altitude EKF is no longer required.
AltitudeHold: use the true altitude desired in the object

Remove the implicit zeroing when engaging the mode.
AltitudeHold: implement tilt compensation

This will increase the throttle with the angle of the quad to
keep the thrust in the vertical dimension approximately constant.
AltitudeHold: use PID library and add Ki term

Using the antiwindup protection on the integral component.
AltitudeHold: cleanup to the timing settings
AltitudeHold: strip this module to only the controller component

The attitude estimation from the baro and accel has been moved to
the attitude module so the altitude EKF is no longer required.

Conflicts:
	flight/Modules/AltitudeHold/altitudehold.c
	shared/uavobjectdefinition/altitudeholdsettings.xml
AltitudeHold: use the true altitude desired in the object

Remove the implicit zeroing when engaging the mode.
AltitudeHold: implement tilt compensation

This will increase the throttle with the angle of the quad to
keep the thrust in the vertical dimension approximately constant.

Conflicts:
	shared/uavobjectdefinition/altitudeholdsettings.xml
AltitudeHold: use PID library and add Ki term

Using the antiwindup protection on the integral component.
AltitudeHold: cleanup to the timing settings
AltitudeHold: documentation
UAVOHoTTBridge: use VelocityActual instead of AltHoldSmoothed

Also removed the altitude offset calculation as it should not be
needed as PositionActual will zero on the ground.
AltHoldSmoothed: delete unused object