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

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

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.

- Logging now always on to temp file
- User prompted to save temp file after disconnect
- Orphaned temp logs checked for on boot
- Logs saved to new save file location
- Log file starts/stops with first and last connnection

Changed many functions in the abstract *Link classes to be const. This facilitates setting other functions as const. The metadata for specific links are reset when the links are added.

The details on the success/errors for the MAVLink protocols are now shown for each link as tooltips that are updated every 5s. Values are currently wrong and unsure why as of yet.

Changed many functions in the abstract *Link classes to be const. This facilitates setting other functions as const. The metadata for specific links are reset when the links are added.

The details on the success/errors for the MAVLink protocols are now shown for each link as tooltips that are updated every 5s. Values are currently wrong and unsure why as of yet.

Refactored part of MAVLinkProtocol::receiveBytes() as I was trying to debug within it. Nothing major, though I did remove an unnecessary loop.

Enabled visualization of point cloud data via Protocol Buffers serialization and extended_mavlink_message.

Fixed roll angle in Google earth, still not smooth. Fixed a number of threading issues. Fixed all custom widget related bugs. Improved MAVLink decoder. Reduced CPU usage substantially across all views

Added angle conversion testing, added battery settings option, added option to set MAVLink ID of groundstation

Added not yet working version of logging / log replay, fixed ALL bugs in main window, enabled full persistence in main window and serial link.

Working on QGraphicsView-based local waypoints interface supporting drag-and-drop, commented code, fixed Google Maps interface, added mouse and SpinBox zoom to HSIWidget, fixed MAV-based coloring and stylesheets - MEGA COMMIT

Cleaned up communication structure significantly, should now be easier to add new links. Signal bytesReceived(link, QByteArray) is now only way to pass on newly received data