Enable vtk FFMPEG module if cdat builds or uses FFMPEG
Use CDAT_BUILD_LEAN instead of checking for MPEG explicitly.
Build FFMPEG as shared library for VTK.
Add clt demo plots
Merge pull request #732 from UV-CDAT/vtk_enable_ffmpeg

Vtk enable ffmpeg
thx @ThomasMaxwell commit changes look good since you rebuilt and it works for you I'm approving the merge