Disabled opencl on x264 and ffmpeg build

This modification allows a build to proceed after opencl support has been detected by the x264 build. This is directly related to https://github.com/bytedeco/javacpp-presets/issues/19
Merge pull request #23 from mondain/patch-2

Disabled opencl on x264 and ffmpeg build
 * Disable DocLint, which prevents the build from succeeding on Java 8 (issue javacpp#5)
 * Replace `install_name_tool` hack to set `@rpath` on Mac OS X with patches to do it properly on install (issue javacpp#6)