cupid: fix error when findclumps with jsacat finds 0 clumps.

The section of code that copies history etc. from the input to the
output JSACAT was not checking that nclumps was 0, and therefore
produced an error when no clumps where found. This fix checks that
nclumps evaluates to True before it copies anything in.
cupid: extractclumps now supports the SHAPE parameter

Also the jsacat will be more similar to that produced by
findclumps, the output now supports QUALITY=EDGE and cupid
copys the history into the jsacat.
cupid: add shape and nclumps parameters to extractclumps

This shoud have been in a previous commit (0fdfe05f7ca38...) that
added these parameters to the c function, but I forgot to add
cupid.ifd.in to the commit.
smurf: SMURF depends on thr
smurf: clobber MOC files

jsatilemoc now writes MOC files with the clobber option enabled.
This was requested by SFG so that jsatilemoc behaves in a more
Starlink-like manner and overwrites its output file when
necessary.