Add SequenceTable to the tables

SequenceTable contains the wording for the different types of sequences
on which the stars can be.
Add Star.findsequence()

Add a class method to Star that finds the sequence the star is on. This
will be used in future calculations, and is stored in the private
variable __SeqIndex (which, incidentally, can then be used to get the
wording out of SequenceTable).