Adding support for producing html file outputs.
INCOMPLETE: not sure how to specify how to write the output file for '.html'
not sure how to/if can require only html flag
There are still several major issues -
MSE cards look decent, but there is virtually no text prettification.
Split cards (bsides) are not supported at all.
There is no abuse of the notes field to dump additional data yet.
Removed snow mana from land mana cost.
Planeswalkers almost done; need to handle those with loyalty costs above
9.
titlecase.py provides much better capitalization for names and
rulestext.
Choices now have dash and bullet points.
