- revert once #10590 is resolved properly

* jenkins: decrease VTOL mission alt and FW mission use simple land wps
* startup: decrease min airspeed scaling factor for landing
* jenkins: FW mission include loiter_to_alt cmd

Move ros logs dir so that .ulg files are not in the same directory
(mission_test.py:: get_last_log() fails otherwise)

* land after offboard flying complete
* lengthen rostest time limit for tests (5 min ea)

if the vehicle doesn't land and disarm at the end of the mission, the current sequence doesn't reset to 0

* 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

* add more logging to help with #8556
* log subscribed topics on mission start and test exit (pass or fail)
* use mavlink enums everywhere to avoid maintaining dictionary mappings and to have readable values
* log when the FCU advances to next mission item without satisfying the position reached offset/radius
* some renaming for readability
* log more state value changes (connected and MAV_STATUS)

-created a test base class to centralize redundant methods among the different tests
-added mission waypoint list topic listener (this also helps make sure the simulation is ready)
-check number of mission waypoints in FCU against mission
-increase time for mavros topics to be ready from 30 to 60 seconds
-reduce position check loop rates
-clean up logging
-support QGC plan for mission file format, see #8619
-vehicle is an arg for mission test launch file, working toward other airframes
-Jenkins: fix vtol vehicle arg value
-get MAV_TYPE param and use FW radius for pure fixed-wing mission position check
-remove unused vehicle arg from test in multiple tests launch, clearing runtime warning

 - update to latest sitl_gazebo

thread for offboard publishers, add asserts for topics to come up (simulation ready) and set mode and arming, use home_position topic as better indicator of when the simulation is ready, add more feedback to rosinfo, make timeouts meaningful (in seconds), add land and extended state values

During px4tools installation, the latest version of pandas is
installed, which requires numpy>=1.9.0. Pandas installs the required
version, however, due to the presence of the old numpy in the docker
image, the present version 1.8.2 is used, which leads to an error
when importing pandas.

This commit fixes the problem by explicitly upgrading numpy before
px4tools installation.

Signed-off-by: Andrey Korigodsky <akorigod@gmail.com>

This changes the shebang of the integration test files to python2
because the scripts fail on systems with Python 3 as the default.

Even though ROS has been ported to Python 3, there are still some
dependencies not playing along.

The error that comes up when starting with Python 3 is:
> No module named 'mavexpression'