This allows you to add XY graph plots of any data.  For example,
x,y position data of a servo.

There's no need to create multiple signals - connect() is fine with
connecting styleChanged(MainWindow::QGC_MAINWINDOW_STYLE)  to a slot
with no parameters.

Clean up when exactly we should save settings, and add in checks to make sure we do not do it incorrectly

This fixes a bunch of bugs with setting the title for widgets, deleting
widgets, etc.  It also reduces the amount of code duplication, which is
always a good thing.

The JoystickWidget now has a parent so that it gets cleaned up when the MainWindow is closed preventing zombie-dialog syndrome.

The JoystickWidget now has a parent so that it gets cleaned up when the MainWindow is closed preventing zombie-dialog syndrome.

Partway through refactoring of UAS deletion. This is in order to actually support removing UASes from QGC, which is currently impossible.

Partway through refactoring of UAS deletion. This is in order to actually support removing UASes from QGC, which is currently impossible.