Merge pull request #2351 from mdboom/misc/clang-analyzer

Miscellaneous things caught by clang-analyzer.
Conflicts:

	astropy/io/votable/src/tablewriter.c
	astropy/utils/xml/src/iterparse.c
	astropy/wcs/src/pyutil.c
	astropy/wcs/src/wcslib_wrap.c

git-svn-id: http://svn6.assembla.com/svn/pyfits/branches/3.2-stable@2681 ed100bfc-0583-0410-97f2-c26b58777a21