Copyright notice for rg_etc1.

rg-etc1 has been originally written by Rich Geldreich <richgel99@gmail.com>
in C++ and then converted to plain C by the EFL team to fit the rest of
the EFL.

The original code comes from:
https://code.google.com/p/rg-etc1/

For the ZLIB license below, see http://opensource.org/licenses/Zlib

Copyright (c) 2012 Rich Geldreich

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.