bringing comments up to date with editflow change

Resolves #228. See:
https://github.com/Automattic/Edit-Flow/commit/3d7b066f7b851acbc9aa98855277e7cda6a7d4b6#diff-c8a5103bf9d86845d8f9e617274be5ea
Activates DOMDocument's own very special buffer

Let me be perfectly clear. DOMDocument can take it's stupid weird need
for its own special buffering and shove it right where it can't parse
standard symbols correctly. We really really really need to find a
better tool to use for this. Until then, resolves #229

Also, at long last, should negate the need for the BIG FREAKING WARNING
at
https://github.com/PressForward/pressforward/blob/ec5f8a6145560ad4d8fecf274b37dd90f0ced09e/includes/readable.php#L125