* Add kdevelop to gitignore
* Add test stubs
* Rename px4_add_gtest to px4_add_unit_gtest
* Add infrastructure to run functional tests
* Add example tests with parameters and uorb messages
* Fix memory issues in destructors in uORB manager and CDev
* Add a more real-world test of the collision prevention
This moves the hysteresis test out of the systemlib and makes it its own
small library. Since it still depends on hrt_absolute_time this does not
link yet. My attempt to get all link dependencies together failed.
Julian Kent