Fix title parsing in refactored parser
Better parsing of parenthesised lines (usually subheadings)
Fix #3 by correcting bad titles followed by parens

Having done refactoring, we have the chance to run transformParens on
the intermediate representation and change nodes that look like:

  Continuation
  Parens

into

  Title
  Parens

We exclude cases where the Continuation started with a number, as it's
probably actually a list.