First stab at SVG filters.
Avoids double AVM1 context initialization
Refactors AVM1 _root and _level0 properties.
Disables "avm1-moviecliploader" test
Merge pull request #1787 from yurydelendik/avm1loadclip

Fixes loadClip and proper _root resolution for child movie
Add drop shadows and fix but related to filter distance units on retina displays.
Add acid test.
Merge pull request #1784 from mbebenita/filter

First stab at SVG filters, WIP.
Fixes AVM1 gotoLabel operation.
Merge pull request #1788 from yurydelendik/avm1gotolabel

Fixes AVM1 gotoLabel operation.
Merge pull request #1789 from tschneidereit/master

Bug 1080313 - Follow up to fix even more breakage
Fix blur scale for different quality levels.
Merge pull request #1790 from mbebenita/filter

Fix blur scale for different quality levels.
Make Add blend mode fall back on Overlay instead of Normal.
Merge pull request #1791 from mbebenita/filter

Make Add blend mode fall back on Overlay instead of Normal.
Fixes but related to removing filters.
Merge pull request #1792 from mbebenita/filter

Fixes but related to removing filters.
Gracefully handle invalid clipping masks
Fix hit testing bug involving clipping masks with multiple children