#1 Exceptions when Range check enabled

[Yann Papouin]

Hello,

First thank you for this library, it's a really good work.
I'm posting here to report some issue with your library when range check is enabled.

When loading a PNG file (eg: basi0g04.png) I'm getting ERangeError in procedure TPortableNetworkGraphic.LoadFromStream(Stream: TStream);
I fixed this with the patch attached

[Yann Papouin]

Fix