- Updated to use RCChannelWidget
- Removed attitude control widgets
- Previous calibration values now shown when not actively calibrating

Left QGCRadioChannelDisplay alone so that I didn’t need to modify all
the other APM board code which uses this control. Also new control only
support horizontal orientation, with no plans to add vertical.

Path through code allowed for xmlfile to be used when file was not
opened. Also changed qWarning->qDebug to allow QT_FAIL_WARNINGS to be
used to find bugs.

This way we can test with QT_FAIL_WARNINGS set.

Plus a few API tweaks

Also updated to latest QGCUASFileManager implementation.

Tried to order items in order of importance.
Also all perspectives now have their own shortcuts.

Both on the backend (replaced with DEFAULT view) and on the front end (removing UI menu items).

Includes removing an if-statement that should've been dead but was erronously applied to the following statement. Dead code = bad, if-statements without braces = bad.

This was deprecated on Febuary 3rd, 2014 and removed a little later. This finally completes that process.

Without this, when you go to airframe config and the current config is
Simulation it will not be selected. Hence you won’t know what the
current config is.

I don't think it's needed anywhere in QGC since this has been a bug for a long time.

SLUGS has maintained their patches out-of-tree for a long while now.
These will eventually get merged back in, but it'll be easier to evaluate them as fresh commits instead of modifications to this old & dead code, so we'll delete this for now.

this adds an option to select the mode of the joystick in the joystick
config widget. The mode sets the setpoint type which is sent when moving
the joystick.