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In order to build pion with CMake and Visual Studio 2012 i stumbled on- and fixed some issues. I want to use pion with logging disabled to get rid of any dependency. Additionally, I added the option BUILD_SPDY basically to get rid of the dependency to zlib. I reached this by removing the source files containing the SPDY implementation - this would better be the other way round by explicitly/selectively adding the needed source files (as recommended by CMake).