It's not desired to have automatic log streaming for several reasons:
- There's already SD logging (which is the case for the majority of the
  users)
- The link does not provide the necessary bandwidth (eg. wireless telemetry)

* Some code moved to Vehicle

* Moved from UAS
* Remove unused code

* Make MainToolbarIndicators reusable by other views
* Change to font based ratio sizing

This prevent the visibility change from trashing source setting

Shows horizontal/vertical scroll indicators

* Vehicle selection must be global control
* Disconnect controls must be associated with Vehicle

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