added most multi letter spectral classes to spectral type code
added binary support to example classes.
changed transit method detection to use is transiting tag implemented in catalogue version ee12343381ae4106fd2db908e25ffc537a2ee98c (11th March 2014)
added all tags used in the catalogue. To do this new classes containing the common tags and operations for each class were added. No tests that these work yet (although no previous tests fail)
added params object with estimateMissingValues = True. Included tests to check that turning the flag off works correctly.
updated readme (and error message in database)