ENH: Remove building the MPEG2 library from VTK's build instructions. This...
ENH: Remove building the MPEG2 library from VTK's build instructions. This library has patents associated with it, so it should not be *included* in VTK. Make it available separately for clients who are willing to accept using patented code. Change use of the MPEG2 library to be based on a CMake configure-time option: VTK_USE_MPEG2_ENCODER. This set of changes is to conform with VTK's "patent free" policy which prohibits including patented code in the VTK source tree.