* libgimp/gimp.c (gimp_run_procedure2): fixed a memory leak,
        (gimp_destroy_paramdefs) new function.
        * libgimp/gimp.h (gimp_destroy_paramdefs): added header.
        * libgimp/gimpfeatures.h.in (GIMP_HAVE_DESTROY_PARAMDEFS): new macro.
        * plug-ins/script-fu/script-fu.c (init_procedures): fixed a
        big memory leak (this also applied to perl!)