tempdir and tempname are required for Matlab compatibility. The Mathworks
doesn't have a tempfile so we are free to do what we wish in this regard.
Right now, the name accords with the underlying C function name. But it
could make sense to settle on "temp" as the prefix for all temporary things
and rename this to tempfile. It would make it easier from the command line
to use temp<TAB> to see what functions are available. On the other hand,
tmpfile is in all the seealso links so if you're searching you will come
across it quickly.
Anyways, I'm not too exercised either way. If someone wants to prepare a
changeset I'd review it. Otherwise it can stay this way.