Updated sitelock failure screen.

Improved the visuals of the failure notice.
Revised the default failure notice text.
Enabled easy customization of the failure notice text and formatting.
Provide example for customizing title/body text.
Added since tags for 4.3.0.
Changed UInt to FlxColor for color-based arguments.

Fix Travis build break against Haxe 3.2.0.
An Array<Int> is not being converted to a Vector<Float> when compiled with the older version of Haxe.  Making the first element an explicit floating-point value will force the type to Array<Float> which, hopefully, should convert as expected.