// picoPNG version 20101224
  // Copyright (c) 2005-2010 Lode Vandevenne
  //
  // This software is provided 'as-is', without any express or implied
  // warranty. In no event will the authors be held liable for any damages
  // arising from the use of this software.
  //
  // Permission is granted to anyone to use this software for any purpose,
  // including commercial applications, and to alter it and redistribute it
  // freely, subject to the following restrictions:
  //
  //     1. The origin of this software must not be misrepresented; you must not
  //     claim that you wrote the original software. If you use this software
  //     in a product, an acknowledgment in the product documentation would be
  //     appreciated but is not required.
  //     2. Altered source versions must be plainly marked as such, and must not be
  //     misrepresented as being the original software.
  //     3. This notice may not be removed or altered from any source distribution.