Merge pull request #412 from Gama11/dev_FlxU

Introducing util package
Merge pull request #413 from Gama11/dev_FlxU

Moved more functions from FlxPTColor to FlxColor + consistent order of v...
FlxTypedGroup atlas setter fix
FlxBasic updateAtlasInfo() fix

it caused app crashes in some cases
Removing old temp fix for srand on neko target

since neko target has 32-bit integers
FlxPoint import for FlxEmitter
Added @:isVar to FlxButtonPlus x and y so they can be accessed from a derived class

thanks @ProG4mr for it