fixed writeBytes default arguments, cleaned up readBytes'
Transparent background by default

A transparent root element is useful for Preloaders and 3D Contexts.

Reasoning that a default value of 0 transparency is fine for all cases because backgroundColor value is determined from reading the containing div's style tag (line 258).  So if it's been set then the CSS already exists to set it as that backgroundColor (or backgroundImage) by following the default CSS flow.  If, on the other hand, the backgroundColor has not been set then the default CSS behavior of transparent should be followed.

The drawRect is still needed for the hitTest events as the original comment states.
BlendMode.ADD for BitmapData.draw()

Provides basic ADD compositing for draw function.  No other BlendModes are supported so this may be hacky in isolation?  Likewise no consideration has been given for none draw methods (i.e. DisplayList).
Update ColorMatrixFilter.hx

got error /usr/lib/haxe/lib/openfl-html5-dom/1,2,0/flash/filters/ColorMatrixFilter.hx:11: lines 11-62 : Field __applyFilter is declared 'override' but doesn't override any field
Override fixed
Stage background color fix
Update BlurFilter.hx
Added createBox()
Fix CI script
Rectangle.setTo() added
Merge pull request #60 from Gama11/Rectangle.setTo

Rectangle.setTo() added
Merge pull request #59 from BigZaphod/master

Added createBox()
Merge pull request #57 from zaynyatyi/master

Update ColorMatrixFilter.hx
Merge pull request #52 from hypersurge/patch-2

BlendMode.ADD for BitmapData.draw()
Merge pull request #51 from hypersurge/patch-1

Transparent background by default
Merge pull request #50 from clemos/master

fixed writeBytes default arguments, cleaned up readBytes'
Minor cleanup
added type image/gif to loadFromBytes
Merge pull request #61 from tesract/patch-1

added type image/gif to loadFromBytes
Compile fix