Used for unit testing

This allows us to create mock version of the objects to use for unit
tests

Unit test changes

I have UI based unit tests coming, so getting ready for that

- debug builds always compile unit tests in
- seperate qgcunittest.pro is no longer needed
- found out the hard way that you can’t use debug or release as a
scope. You need to use the CONFIG(debug,debug|relase) macro (in this
example to test fro debug). Reason is that debug and release show up
multiple times in CONFIG, last debug wins. This is what the CONFIG
macro does. Without it, it’s luck as to what you get. I found OSX was
getting debug, Linux was getting a debug build, build into release
directories. QT_DEBUG set randomly. Lot’s of problems.

Add data rate calculations for all LinkInterface-derived classes

add eclipse settings folder to gitignore file

Fix broken Windows build

- 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

Converted LinkInterface from a pure-virtual interface into an abstract base class. This centralized the data rate calculation code for all subclasses. Also added the necessary code to provide upstream/downstream data rate calculations for all LinkInterface-derived classes.

Remove hardwired inclusion of OSG

The remainder of .pro and .pri files have conditional inclusion of
OpenSceneGraph bases on availability. Removed this line which always
includes it and overrides the conditional include which is already in
other parts of the make files.

Add display of the upstream data rate to the Debug Console

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.

Altitude and speed rewrite

Removed LinkInterface methods which were never being called. Updated var...

Unit Tests would not compile, once they compiled, they didn't work correctly, once working correctly they found a couple bugs

Expose SYSTEM_TIME message to QGC

Use TARGET instead of hardcoded qgroundcontrol.app name. This allows
this file to build unit test app as well as qgroundcontrol app.