Generic AutopilotPlugin full implementation

Delete unused files

No longer needed with move to summary page qml

Vehicle Summary is now QML

Summary page is also the launching spot for the setup screens. No more
left hand set of buttons.

This prevents mavlink signals from being emitted after link is
disconnected

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

- properties now hand off of main “autopilot” object in qml
- Added support for summary items through qml

simplify instructions to clone the repository

Switch parameter facts to QVariantMap

This way you don’t need to know parameter set ahead of time.

Ptr fix - fixes #1117

Combined pulls #1113 and #1115

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.

New Singleton Manager

Support enabling fatal warnings via user_config.pri file

Restructure LinkManager/MAVLinkProtocol

Give user choice to disconnect all links on MainWindow close

Needs to be re-written

Put audio output into a worker thread.

Bump Linux Qt requirement to 5.3 in README