Added dialog for editing script parameters.  Added tile aliases and rules.

Scripts have a params() function that returns a list of parameter keys.
Script parameters can be edited in ScriptParamsDialog.

The 'Add Script' command is now a submenu of scripts that may be added.
Update WorldChunkMap when script parameters change.

This isn't right atm, the old script parameters can't be restored by undo.
Q_UNUSED everywhere.
Fixed IsoPathRenderer not using the level in toScene().