Version 4.0 - beta 4

Fixes and Improvements

• Fix Arcade Physics group collisions, nearest and furthest, and static group refresh. Thanks samme!
• Fail gracefully when a texture isn't created in addBase64()
• Improve RenderSteps initialization, removing a private method substitution
• Fix Layer's use of RenderSteps
• Fix reversion that removed camera zoom on separate axes
• Fix filter padding precision
• Fix filter padding offset with internal filters
• Improve TransformMatrix.setQuad documentation
• Fix shader not switching when TilemapLayer and TileSprite are in the same scene