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
Merge pull request #57 from zaynyatyi/master

Update ColorMatrixFilter.hx