Invalid time stamps for faster-than-real-time

[el3ment]

The following files use ros::Time::now() and therefore create some problems when running faster-than-real time.

https://github.com/byu-magicc/ros_copter/blob/RC1.0/src/controller/controller.cpp#L119

https://github.com/byu-magicc/ros_copter/blob/RC1.0/src/waypoint_manager/waypoint_manager.py#L31

https://github.com/byu-magicc/ros_copter/blob/RC1.0/src/ekf/ekf.cpp#L69

https://github.com/byu-magicc/ros_copter/blob/RC1.0/src/ekf/ekf.cpp#L124

https://github.com/byu-magicc/ros_copter/blob/RC1.0/src/ekf/ekf.cpp#L412