sc: NodeProxy2: implement changing definition while running
sc: prototype NodeProxyDef2
sc: NodeProxy2: consolidate cleanup
sc: NodeProxy2: implement on-the-fly remapping of controls to source
sc: NodeProxy2, NodeProxyDef2: streamline changes while running
sc: prototype PatchEnvironment, remove NodeProxyDef2
sc: support FuncProxy within PatchEnvironment via FuncDef