New VehicleLinkManager implementation

Mavlink update

Clean up references to MainRootWindow globals

Full BATTERY_STATUS support

Comp Info support for http downloads

Support comp info param metadata and gzip json

Harden FTPManager::download against packet loss

Component Information FTP download support

More work on vehicle connect state machine(s)

New initial connect state machine which supports COMPONENT_INFORMATION

LinkInterface and Vehicle uses mutexes to synchronize writing bytes to the link instead of queued signals

Set RC To Param support

Add support for chunked STATUSTEXT

Unit test for mission transfer error string checking

Mavlink terrain protocol support

64 bit fixes

qobject_cast is times faster dynamic_cast for objects that
inherit QObject. also, use auto keyword to not duplicate
class names.

Map gimbal controls
Keep track of gimbal position within Vehicle

Use offline editing params for MockLink

Add support for ArduRover MockLink

Support STATUSTEXT_LONG

16 RC channels

Support parameters from multiple components

* Flight modes still not implemented. Waiting on message change.
* Also includes various cauterization of UI things which should not be
available on high latency link.

Fix merge issues

This reverts commit 52160d80.