Revert to CFITSIO for table i/o using a re-usable cfitsio library

[olebole]

This is an alternative to #379: it switches to cfitsio for tbtable, but installs cfitsio in vendor (where it was until 2.17.1). This has a few advantages:

• cfitsio as a system dependent package is not part of pkg (general application packages),
• cfitsio can be easily updated,
• cfitsio may be used in other packages (st4gem, fitsutil), providing a single source.

This is also for discussion with @noirlab-iraf-admin resp. @mjfitzpatrick for clarification with NOIRLab IRAF. Original statement to switch to cfitsio in tbtable by @mjfitzpatrick in 5d4c168 :

The libtbtables.a was changed in v2.16 to use SPP fitsio from earlier uses of the fortran version under the assumption that they were equivalent. However, there is a bug in the fortran version of ftdrow() when called by the TDIFFER task in which the output table doesn't have its NAXIS2 value properly updated for FITS tables causing the task to exit. The cfitsio code acknowledges the value may not be correct and so uses an internal data structure value for the 'nrows' rather than the keyword, but equivalent functionality does not exist in the fortran version. A similar problem exists when inserting rows but this is not called from any existing NTTOOLS tasks.

This change fixes a bug in the GEMINI.GSEEING task which is the only task known to call TDIFFER.