Change logic for determining if ascii table should be masked
Change DAOphot to mark INDEF column values as missing (masked)
Add tests of INDEF and type changes to DAOphot reader
Fix python 3 and numpy 1.4 problems in io.ascii read tests
Merge pull request #511 from taldcroft/daophot-indef

io.ascii daophot pprint crashes on row with INDEF