Various fixes due to changes in text at TfL end.

* "Leaving * towards *" now also given as "Leaving *, heading to *"
  or "Leaving *, heading towards *", sometimes without the comma.
* Also using 'due' as well as '-'.
* Extra stuff in <P> that we don't care about.
* "Warren" for "Warren Street"
* "Harrow-On-The-Hill" variant
* "Finchley Central on the Southbound road"