transformed them into the initial_indent and subsequent_indent instance
attributes. Now they actually work as advertised, ie. they are
accounted for in the width of each output line. Plus you can use them
with wrap() as well as fill(), and fill() went from simple-and-broken to
trivial-and-working.
and fill() methods. Keep interface of existing wrap() and fill()
functions by going back to having them construct a new TextWrapper
instance on each call, with the preferred width passed to the
constructor.
sentences are separated by two spaces.
Improve _fix_sentence_endings() a bit -- look for ".!?" instead of just
".", and factor out the list of sentence-ending punctuation characters
to a class attribute.
