CALSTIS Release Notes v. 2.29

PR 64665:  CALSTIS opens a table but doesn't close it.
PR 64666:  CALSTIS tries to get a string-valued keyword as an integer.
PR 64780:  Calstis7 does not initialize tds_starti.

There is a function that opens an image extension just to check
whether the extension exists, but this function failed to close the
table.  This hasn't caused a problem in the past, but if CFITSIO is
used instead of IRAF for the image I/O as well as for tables, an
exception is raised when an image I/O call tries to open the file
read-write, because it's already open read-only.

In calstis2, there is a check that all the input files and image
sets are the same mode, and one of the tests is on keyword CCDAMP.
The value of that keyword is gotten as an integer, but the keyword
value is a string (e.g. 'D').  The call to get the value returns
status = 1 (i.e. bad), and no check is actually done on the values of
CCDAMP.  This has been fixed.

A variable tds_starti in absflux.c was not initialized.  Instead,
thr_starti was initialized twice.  The second thr_starti has been
changed to tds_starti.