Merge pull request #806 from mbebenita/master

JSON fixes and makes GIRP sort of work.
Enable all those shiny trace tests we have had for TextField for quite a while now
Apply TextField#multiline property during content parsing, not during rendering

The Flash Player ignores `multiline` for content set via the `text` property (so that's always rendered with line breaks intact). And it uses the setting that was active when content was set, not the one active when content is rendered.
Support some scrolling-related TextField properties

 - maxScrollV
 - maxScrollH
 - numLines
 - scrollV (stubbed)
 - scrollH (stubbed)
 - bottomScrollV (stubbed)
Much-improved handling of font metrics

With lists! Long, exhausting lists! Of font metrics! Per OS!
Merge pull request #810 from tschneidereit/master

TextField fixes and support for additional properties
Ignore bounds of empty shape paths.
Fix stage bounds.
Merge pull request #811 from tobeytailor/gfx

Fixes bounding calculation
Set Loader URL from URLRequest.