Doxygen documentation support

To run:
Enter Core directory
run 'doxygen' on a terminal
Core: Add Guided_Velocity control
Merge pull request #1208 from arthurbenemann/doxygen

Doxygen documentation support
Desktop: Catch possible NPE
Core: added structure to hold the footprint locations in the Drone object

Conflicts:
	Core/src/org/droidplanner/core/drone/DroneImpl.java
	Core/src/org/droidplanner/core/drone/DroneInterfaces.java
	Core/src/org/droidplanner/core/model/Drone.java
Desktop: Plot the camera Footprints on the map
Merge pull request #1209 from arthurbenemann/nav_velocity

Guided Nav velocity
Merge pull request #1210 from arthurbenemann/camera_feedback

Camera feedback
Core: add camera trigger functionality
Merge pull request #1211 from arthurbenemann/cameraControl

Core: add camera trigger functionality
fixed location of the side panel drawer image.
Merge branch 'master' of https://github.com/DroidPlanner/droidplanner into ui_cleanup
fixed location of the side panel drawer image.
removing unused dependency from the mavlink project.
removed unused menu resource file.
restricted the info bar menu to the flight activity.
fixed miscellaneous crashes.
moved the editor toolbar to the action bar.
multiple bug fixes related to the editor toolbar.
adding forgotten drawable resources.
added mission command editor tool.
updated the ui for the editor info window, and tool mission item typ spinner.
updated the ui for the editor info window, and tool mission item typ spinner.