Reasons:
- DeviceMaster::_node_map does not need to be shared among instances,
  because there is at most 1 instance per Flavor and different Flavors
  have non-intersecting device paths.
- Keeping it static would also require a static lock
- DeviceMaster::_node_map was not locked at all when used from
  uORB::Manager

So this fixes two synchronization issues:
- Different DeviceMaster objects could access the same static data in
  parallel
- getDeviceNode() called from uORB::Manager did not use any locking at all

This has the following benefits:
- Manager can ensure that there is at most one instance of DeviceMaster
  per Flavor
- The Manager needs access to (static) data of DeviceMaster already.
  This will make it easier to access this data in a non-static way, and
  does not introduce new dependencies.

Fixed some edge cases on the geo_tag_images.py script. Added explanation to the --kml function. Added more examples for the execution of the script.

It uses a queue length of 6. There are 3 RTCM msgs/s, but due to
fragmentation and WiFi lags, there can be more than that. During several
tests, a length of 6 showed no queue overflows.

The mission feasability checker was called with the same arguments
twice which made it hard to understand when a mission is marked valid.

The mission check should run in these two cases:
- When initializing (if home comes up) if there is already a mission saved.
- When the mission gets updated.

This reverts commit a956429c.

This reverts commit 699b6a2c.

* fix VTOL vehicle_status timestamp

* run astyle

The mission feasability checker was called with the same arguments
twice which made it hard to understand when a mission is marked valid.

The mission check should run in these two cases:
- When initializing (if home comes up) if there is already a mission saved.
- When the mission gets updated.

Navigator: Initialize subscription and disallow copy constructors for classes that have pointer members

This brings support for the Ak8963 for Bebop.

Fix missing orb_unadvertise on shutdown
Fix missing closing of file descriptors