Load new entry into panel before showing it, avoids briefly showing the previously loaded entry when swapping between different types
Added ability to specify 'large' versions of program icons (any icon in 'icons/large' with the same filename as an icon in 'icons' will be set as the large version of that icon)
Various additions to SToolBar:
- New toolbar_size cvar to specify the size of toolbar icons (size > 16 will use the large version of the icon if found)
- SToolBarButton can be shown as icon+name
- SToolBarButton no longer has to be tied to an SAction