Added an option to output the image OutputBV + OutputS.

      * src/Args.cc: Get the name for the output image.
      * src/Args.hh: Get the name for the output image.
      * src/TVL0DecompositionMinimizer.hh: Store the image.
      * src/TVL0DecompositionMinimizer.hxx: Store the image.
      * src/main.cc: Save the image.