[ENH] TextStyleName ( [er][sm][et] refactoring recommended )

[germanmorales at delta-sys.com]

The same thing done by this enhancement is already duplicated in the
image:
-StrikeFont class familyNames and actualFamilyNames (perhaps with a more
elegant collection usage)
-TextStyle actualTextStyles (answers a dictionary instead of an
orderedcollection, but the logic is the same)

Perhaps TextConstants could be refactored to a subclass or a decorator
of a Dictionary and then provide additional methods to do this and other
filtering?