Fixes display object validation error from porting TextField changes from the dom-render branch
Change TextField html parsing and rendering to work on a nested tree instead of a linear list of ranges
Revert static textfield rendering to the old, busted way of creating an array of strings representing JS commands in the SWF tag parser. For now.
Implements Canvas-based rich text rendering.

For now, applying formats doesn't work, but setting .text or .htmlText is supported. Exceptions to the support are:

- leading
- blockIndent
- leftMargin
- rightMargin
- bullet points for <li> nodes
- <img>
- <u>
- <a>
- Textfield.stylesheet