Fix CONSTRAINTS_DOC formatting in modeling docs
vos_catalog.py: fix use of format() for compat with python 2.6
another {} format() problem in test_cosmology
Standardize how Python version checking is done.
Add changes to io.fits
Make `@deprecated` decorator work for classes.
Fix pickling issues with class deprecation.  Fix Python 2.6 bug.
Initial commit of the fitshead script

Improved the help text

Improved the help messages and PEP8 compliance

Avoid crashing on a negative HDU extension number

Fixes Python 3 compatibility issue
Added support for EXTNAME/EXTVER HDU accessing and JSON output

removed JSON support; removed os.linesep; tolerate broken pipe errors
removed JSON support; removed os.linesep; tolerate broken pipe errors
Adds support for compressed headers + renamed to fitsheader
Adds support for compressed headers + renamed to fitsheader
Added documentation
Adds fitsheader script and documentation
Adds a test for the fitsheader script
Fixes sphinx build warnings
status -> "param_jac" in NonLinearLSQFitter
Add param_cov to fit_info
Use of deprecated 'key' member in error message

When parsing invalid card, the error itself raises an error due to use of deprecated self.key.
Merge pull request #2175 from bogdanni/patch-1

Use of deprecated 'key' member in error message