Fixed buggy generation/application of changetrees to simulate edits

* The change-tree application code had a glaring bug where changes
  wouldn't be made to a node if it was not an element node. This
  was a leftover from earlier versions of the code which wasn't
  removed during updates to the edit simulation code.

  So, a lot of change trees with "2/3/4" set on comment/text
  nodes were never being applied so far which effectively stunted
  our selser testing strategy by reducing the # of unique randomized
  tests.

* Regenerated blacklist. Looks like more tests are passing now. Most
  of the blacklist changes seems to be shuffling around of output on
  failing selser tests.

     BEFORE         : selser: 13369 passed / 1627 failed
     WITH THIS PATCH: selser: 13490 passed / 1506 failed

* Also updated debug output for the 'dump:changetree' to emit DOM
  before/after changetree application (which is what highlighted
  the bug by showing far fewer changes on the DOM than what the
  changetree indicated).

Change-Id: I73ed5aa55191e3465e229ccf4dc345ec6189abd0
Merge "Fixed buggy generation/application of changetrees to simulate edits"