Add PLACE_UNFILLABLE_HOLD permission

Add PLACE_UNFILLABLE_HOLD permission

And hook it up in JSPac and TPac.

General idea: If you have the permission you can place holds that will not
fill right now, in general, for any reason.

In TPac, I replaced the previous "check the last failure code" line. The
new permission basically accomplishes the same thing for now, and is less
likely to return different results from placement attempt to placement
attempt. Also, only checking one failure code of potential hundreds didn't
make a lot of sense.

In the event of age protected copies the age protected prompt wins out.

Signed-off-by: Thomas Berezansky <tsbere@mvlc.org>