Insert SKELETON.
Prefix ARG allows wrapping around words or regions (see `skeleton-insert').
If no ARG was given, but the region is visible, ARG defaults to -1 depending
on `skeleton-autowrap'. An ARG of M-0 will prevent this just for once.
This command can also be an abbrev expansion (3rd and 4th columns in
M-x edit-abbrevs buffer: "" command-name).
Optional second argument STR may also be a string which will be the value
of `str' whereas the skeleton's interactor is then ignored.
(fn SKELETON &optional STR ARG)