Reorganized UI components
Don't automatically resize split containers in TracksPanel
Reorganized code in FormAsyncControllerTest into regions and renamed buttonMux_Click() to buttonScan_Click()
Mark "best guess" playlists and tracks in bold
Minor/ignore - Renamed buttonCancel to buttonCancelScan in FormAsyncControllerTest
Minor/ignore - Renamed splitContainerWithDivider1 to splitContainerMain in FormAsyncControllerTest
Renamed FormAsyncControllerTest to FormMain
Added bdhero_gui.ico to BDHeroGUI project
Bumped version from 0.5.6.0 to 0.5.7.0