Getting sloppy...

It now shows "Show" or "Hide" Status Bar depending on the current state.

New version using QtQuick along with an experimental Map Background

Also many LinkManager API changes to further isolate all link
management inside LinkManager.

Should fix things.

Moved update canvas signal to perspective load instead of hooking it to the paint event.
Added an "S" as the unit for the number of cells fact (as in 4S).

Although this should theoretically be a no-op it causes a crash in
Windows when running unit tests. Also parent toolbar in constructor.

The goal of this first installment is to organize the code a bit so it's more readable,
clean up a bit of left over cruft, and manage link configurations (and links in general).

Changing the order of the QGCFileDialog::getSaveFileName() function. The idea was to expand the existing QFileDialog version but as we removed the selectedFilter, we might as well make this more intuitive. The options argument is the one trully optional and should be last.
Adding an example to the documentation on how to go about figuring out what file type was returned by these functions.

Removed the “selectedFilter” argument from the QGCFileDialog functions along with references to it in unit tests.
Fixed function declarations and prototypes formatting while at it.
Changed the caption of a few file save dialogs with a more descriptive text (explicitly telling what is being saved).

- Central widget no longer stacked. Views are added/removed to layout
to switch view
- Dock Widgets are globals with single instance of each type
- Both central views and dock widgets are just-in-time created saving
lots of memory

QGCApplication::saveTempFlightDataLogOnMainThread()
MainWindow::startVideoCapture()
QGCBaseParamWidget::saveParametersToFile()
QGCDataPlot2D::savePlot()
QGCDataPlot2D::saveCsvLog()
WaypointList::saveWaypoints()
QGCToolWidget::exportWidget()
LinechartWidget::startLogging()

Making sure defaultSuffix doesn’t start with a dot (i.e. “.bar”)

QGCFileDialog::getSaveFileName()

Assert if defaultSuffix contains a dot (i.e. “.bar”)

UnitTest::_getSaveFileName()

- Central widget no longer stacked. Views are added/removed to layout
to switch view
- Dock Widgets are globals with single instance of each type
- Both central views and dock widgets are just-in-time created saving
lots of memory

Now works for more than Serial links

Moving methods from MainWindow to QGCApplication so that more things
can run without a window. Helpful for testing.

When using DeleteOnClose with a QQuickWidget, the shutdown sequence
causes the MainWindow destructor loop back onto itself.

Plus a large number of other changes to allow for orderly shutdown of
objects without crashes or asserts. This is need for unit tests to
create/delete global state around every test.