* remove non-functional gazebo headless arg
* remove unused namespace args
* simplify mavros launch, use mavros's px4.launch instead
* fix single_vehicle_spawn spelling
* formatting with xmllint: remove empty lines, set intent to 4 spaces, add xml tag for editors, add comments to break up spections
* remove old and deprecated launch files

* add respawn_gazebo arg to be used with empty_world.launch
* catch rospy sleep method's exceptions
* fix copy-paste mistake in land state failure message

Adding files which enable a simulation with the autonomous underwater
vehicle (AUV) from the Technical University Hamburg-Harburg

* Path cleanup for SITL.

* Restructured sitl scripts dir.

* Set integration tests to use ekf2 for vtol.

* Fix sitl paths for mac.

This reverts commit 699b6a2c.

increased fixed wing radius for mission tests and added more informative output for position matching

reorganized posix sitl launch scripts, reorganized mavros python test scripts (integration tests) and updated them for posix sitl, removed old and not working integration tests

- updated tests to work with current setup