Since debug console maintains a list of links it needs to use shared
pointers so it doesn’t run into the link delete ordering problem.

Link ids were being used interchangeably with the mavlink channel for
the link. Link ids handed out as a numerically increasing integer. Once
the counter went past MAVLINK_COMM_NUM_BUFFERS all hell would break
loose and cause memory corruption.

More consistent with Qml usage pattern

This function is called automatically when a QSettings object is destroyed,
so is rarely needed to be called explicitly.

There are still some cases where
a QSettings object is passed-by-reference, so there I left the sync() calls as
it's unclear how permanent those objects are and if they'd call sync() before
application shutdown

Delete of last link would cause crash. Need to check for -1 which
signals no selection in combo box.

- NAN not available in windows headers, use cross platform friendly
version
- VS compiler does not allow initializing non-integral types in header
files
- ActiveQt libs are already installed by Win Qt4.8.5, no need to build.
Plus this part of the makefile just loops without nmake.exe installed
which is not part of a standard windows box

Renamed getNominalDataRate to getConnectionSpeed. Also added upstream/downstream data rate functions to all Link classes.

Simplify calculations by assuming we only care about rates in kB/s.

Hotfix: Fixed widget / UAS initialization order which led to text messages (and other updates) being ignored if the widget was not open when the UAS was created

Erros casused by all of the mergedd branches are now fixed for qgroundcontrol.pro. Working on fixing the errors that now appeare in qgcunittest.pro.

qgcunittest.pro now compiles and runs as long as run in terminal in projcts->Run Settings is unchecked.