MAVExplorer race condition when processing multiple commands

Running a graph command at the same time as another command (IE Display -> Map) causes a race condition and results in the graph and map both losing data.

The top map and graph were made at the same time, note the outages in the GPS.Status line, and the straight line segments on the map. The bottom graph was created from the same data set without running any other commands at the same time, there are no lost data points on that graph.


Start by reproducing the race condition in MAVExplorer by running a graph command concurrently with Display  Map, then compare the results with a graph run alone. Trace how the graph and map commands process the same data; done means concurrent commands no longer lose graph points, GPS.Status data, or map segments.

Written by the indexing model from the issue text.