Adds regression tests and fix for https://github.com/spacetelescope/PyFITS/issues/27

Conflicts:

	lib/pyfits/tests/test_image.py
	lib/pyfits/tests/test_table.py

git-svn-id: http://svn6.assembla.com/svn/pyfits/branches/3.0-stable@2235 ed100bfc-0583-0410-97f2-c26b58777a21