Merge the changes for ticket 219.

git-svn-id: http://svn6.assembla.com/svn/pyfits/branches/3.1-stable@2157 ed100bfc-0583-0410-97f2-c26b58777a21
Merge branch '3.1-stable' of github.com:spacetelescope/PyFITS into 3.1-stable

git-svn-id: http://svn6.assembla.com/svn/pyfits/branches/3.1-stable@2162 ed100bfc-0583-0410-97f2-c26b58777a21