Merge pull request #4260 from dogmaphobic/customPluginControl

src/api/QGCOptions.h

src/api/QGCSettings.cc

src/api/QGCSettings.h

src/comm/LinkConfiguration.cc

src/comm/LinkConfiguration.h

src/comm/LinkManager.cc

src/comm/LinkManager.h

src/main.cc

src/uas/UAS.cc

src/ui/AppSettings.qml

src/ui/MainWindow.cc

src/ui/MainWindow.h

src/ui/QGCMAVLinkLogPlayer.cc

src/ui/preferences/GeneralSettings.qml

src/ui/toolbar/MainToolBar.qml