Adding commentary to the document renderer
Merge branch 'master' of github.com:Uncodin/bypass into i93-strong-ivars
Intermediary step toward rotatable markdown view

In order to support device reorientation, I did a couple of things
that will help ease the burden:

* Factored out BPDocumentRenderer, it is not done in a UIScrollView
  directly via a function. This has the benefit of sweeping together
  the code that creates views from page frames, and it also trims
  the view heirarchy.
* Added support for asynchronous rendering, such that all Core Text
  rendering is done in a background thread and then displayed
  in UIViews on the main thread when it becomes available. This is
  configurable, since a user will know what kind of display strategy
  is most appropriate based on his or her content. This will help
  in a situation where there is either a very large body of text
  to render, or if there are a lot of smaller markdown views. I
  didn't want to slow down any transition animations because the
  CTFrameSetter was computing the metrics of the given body of text.
* Added easing display so that if the markdown view is configured
  to display asynchronously, it will ease in. Core Text is really
  fast, so it appears harsh to see the rendered text pop into view.
  This fixes the problem by slowly fading it in (where slowly is
  a configurable t).
Gracefully handling rotation and text reflow
Minimizing work performed on rotation
Reformatting code to not spill over page edge
Adding commentary to the BPMarkdownView.[h,m]
Merge pull request #101 from damiancarrillo/i81-rotation

Adding support for orientation