increased verbosity in table.write/table.read errors (fixes issue #590)
This is a rebase / redo based on the IO refactor.  Haven't yet tested
whether _readers and _writers are the right variables; travis will
tell...
Assigning inf and nan as header values simply shouldn't be allowed for now, as this is undefined by the FITS standard (and the previous behavior was nonsensical anyways).  Later this will be allowed optionally.

git-svn-id: http://svn6.assembla.com/svn/pyfits/trunk@2192 ed100bfc-0583-0410-97f2-c26b58777a21
Added changelog entries for spacetelescope/PyFITS#11

git-svn-id: http://svn6.assembla.com/svn/pyfits/trunk@2195 ed100bfc-0583-0410-97f2-c26b58777a21
Add a changelog entry for this fix.
assert_raises -> pytest.raises
Merge pull request #954 from iguananaut/fits-merge

Error when storing IEEE NaN & Infinity in FITS header keywords
This does the trick to fix the new issue that came up with #992.
Add except clause to catch mysterious socket errors
Add "Raises" section to download_file docs
Merge pull request #1097 from eteq/catch-timeout-socket-errors

Catch timeout socket errors in download_file
Support defining lexers in Python files with a magic coding comment.  This works by using  to get the already decoding source lines rather than opening the source file directly using .
Do the same treatment for magic coding comments on yacc
Adds some tests that caught the bug in #590 and fixed said bug.  Factored out some common functionality into a _get_valid_format internal function, and did a bit of pep-8 cleanup while I was in there.
Merge pull request #1096 from mdboom/misc/ply-unicode-file-patch

PLY parsers don't load on Python 3 when the source file contains Unicode and the locale is ascii
Fix formatting issue of docstring
Merge branch 'verbose_tablewrite_exception'