Size reduced from 92878 to 91675 bytes.

CMake added CXX files. Removed those.

Removed ceill patch. ceill is not used anymore.

Removed pkgconfig patch. CMake uses a different file, which does not have
this problem.

Further size reduction to 87938 with LTO.

Removed InstallDev. CMAKE_INSTALL takes care of that.

Added WebP support.

Signed-off-by: Rosen Penev <rosenp@gmail.com>