APM_OBC: update for AP_Mission and AP_GPS changes
Plane: update for new APM_OBC API
build: added -obc supplementary target
autotest: added apm2-obc to build tests
AP_Math: fixed example build
Rover: added BRAKING_SPEEDERR parameter

this controls how much speed error you need before brakes are used
AP_Mission: added get_next_ground_course_cd() API

this gives the ground course of the next navigation leg, which can be
used to calculate the amount of steering required
Rover: use the next navigation course to adjust steering gain in turns

this should make waypoints along a straight path not reduce speed
Plane: show next wp when not running a mission

this lets the GCS know what wp would be run if auto mode is selected
Copter: show next wp when not running a mission

this lets the GCS know what wp would be run if auto mode is selected
Rover: show next wp when not running a mission

this lets the GCS know what wp would be run if auto mode is selected
APM_OBC: removed unused example code
AP_Motors: fixed example build
Plane: fix auto doc unit on GROUND_STEER_DPS
Tools: Update gcc-arm version from q2 to q4

This fixes the installation script since version q2 has been removed
from launchpad.
build: fix paths in install-prereqs-ubuntu.sh

Also upgrade to the latest 2013q4 "GNU Tools for ARM
Embedded Processors" toolchain since the 2012q2 release
is no longer available for download.
Parachute: initial draft library
RC_Channel: add parachute_release to function enum
AP_Parachute: add example sketch

Only tests that the lib compiles
Copter: integrate parachute lib