Closes #50 - Timing Report: Reports false max delay path

* TimingReport would report _first_ max delay path; but there can be
  many, they are ordered by clock in the report
* added RepSeqMatcher to extend SequenceMatcher for Seq[T]
* sorted paths by slack and picked the ones with minimal slack (max
  delay path) and maximal slack (min delay path)
* also fixes minDelayPath, which is pretty useless, however