removed old G_ENUM(), G_FLAGS(), G_NV() and G_SV() macros. added macros

removed old G_ENUM(), G_FLAGS(), G_NV() and G_SV() macros. added macros

Sat Oct 31 05:08:26 1998  Tim Janik  <timj@gtk.org>

        * glib.h: removed old G_ENUM(), G_FLAGS(), G_NV() and G_SV() macros.
        added macros G_STRUCT_OFFSET(), G_STRUCT_MEMBER_P() and
        G_STRUCT_MEMBER() for handling structure fields through their offsets.
        (struct _GHookList): added a hook_free function member, that can be used
        to free additional fields in derived hook structures.
        g_hook_free(): if hook_list->hook_free != NULL, call this function prior
        to freeing the hook. (this functionality should have been there in the
        first place, it just got forgotten as an implementation detail).