AC_PosControl: remove debug
Copter: remove unused var from acro
Copter: implement auto_land with Loiter controller
Copter: LAND at stopping point instead of curr pos
AC_WPNav: set wp origin to horiz and vert stopping point

Also bug fix to set pos_control's down speed as a negative number
AC_AttControl: alternative get_stopping_point_z
Copter: control_rtl
Copter: integrate control_rtl
Copter: resolve conflict between control_auto, control_rtl states
AC_WPNav: remove unused PID references
Copter: WPNav constructor change
AC_Fence: minor comment fix
AC_Sprayer: minor comment fix
this is a test
Copter: ACRO clean up and mistake fixes
AC_Circle: circle control library
AC_AttControl: make ahrs, ins objects const
AC_AttControl: add rateef_rpy

rateef_rpy takes earth frame rates and applies them to the earth frame
angle targets and then converts them to body frame rates
Copter: add Circle parameter
Copter: control_circle.pde added