GCS coreplugin:avoid loading each configuration twice on startup
GCS systemhealth:Only display missing elements warning once
GCS:uavgadgetinstancemanager renamed loadDefault to forceLoadConfiguration
GCS:uavgadgetmanager selectionActivated refactored

listSelectionActivated renamed to doReplaceGadget
selectionActivated not a Slot anymore
GCS:uavgadgetmanager added doxygen to recently changed functions
GCS:uavgadgetmanager made selectionActivated public
Merge pull request #1147 from guilhermito/GCS_enhancements

Gcs enhancements