hector_quadrotor_model: fixed copy&paste error in
quadrotor_aerodynamics.cpp
hector_quadrotor: updated branch information in hector_quadrotor.rosinstall
Revert "hector_quadrotor_model: set drag torques to zero"

This reverts commit 0605cef975d04a214620576e9c522cd09dd6f7f4.
Merge branch 'hydro-devel' into ros_control