Ready To Fly support based on MAV_SYS_STATUS_PREARM_CHECK

Re-architect toolbar for better customization capabilities. Also use less real estate.

Rework Fly View into separate layers which can be customized at each layer.

Restore QGC to its normal UI layout (buttons on toolbar)

Get rid of QGCView, QGCViewPanel and FactPanel. All messages and dialogs are now handled in the root window.

Made QGCCorePlugin derive from QGCToolBox and expose everything through the same mechanism as everything else.

Too complicated supporting both modes as editor becomes more complex

- You can now cancel parameter change
- Tablete friendly