fuse() now expects a pointer as the argument to a fuse function. If
this is one of the functions that takes int, fuse() follows the pointer
and stores that value in the f_list slot, in the integer field of the
argument union. When the fuse goes off, do_fuses() recognizes the
function and passes it the integer field instead of the pointer.
This has the disadvantage of hard-coding the functions that require int
in daemon.c, but since the int is copied into f_list, it no longer has
to be in static or global memory, which simplifies several files.
