Updated Propify! Plugins

GetModel*Array now returns INVALID_HANDLE when attempting to clone a
nonexistent handle (if attempted to call externally from, say,
OnPluginStart()).

Also moved proplist loading to be called in OnAllPluginsLoaded().
Updated Propify!

Added config handler scoping -- registering a handler now supports
restricting key/value reads to certain prop lists.  By default, it only
reads from the current map.