Merge pull request #2193 from bsipocz/fixing_issue_1597

FITS_rec objects can be pickled with this patch
Conflicts:

	CHANGES.rst
	lib/pyfits/column.py
	lib/pyfits/tests/test_table.py

git-svn-id: http://svn6.assembla.com/svn/pyfits/trunk@2668 ed100bfc-0583-0410-97f2-c26b58777a21
Cherry-picked some changes from the in-progress fix for
https://aeon.stsci.edu/ssb/trac/pyfits/ticket/42
that were necessary to get comparerecords() to work properly in Python 3
on tables containing zero-width columns.

This slightly modified the original fix for #2193 in that it allows
phantom columns to be copied as well.

Conflicts:

	lib/pyfits/fitsrec.py

git-svn-id: http://svn6.assembla.com/svn/pyfits/trunk@2669 ed100bfc-0583-0410-97f2-c26b58777a21
Changelog entry for this fix

git-svn-id: http://svn6.assembla.com/svn/pyfits/trunk@2670 ed100bfc-0583-0410-97f2-c26b58777a21