Started the multi cell idea.

		* src/TVL0DecompositionMinimizer.hxx: Small bug
		* src/main.cc: Implementation of the method.
Multi cell is now working. Need to clean that a bit though.

	  * src/main.cc: Corrected bug related to the copy of tmp solutions to
	  the whole image.
New class to handle multi cell computation.

    Not working and documented yet.

    * src/ComputeByParts.hh: New.
    * src/ComputeByParts.hxx: New.
    * src/main.cc: Use it.
Added some documentation.

	  * src/ComputeByParts.hh: Mostly here.
	  * src/ComputeByParts.hh: few fixes.
Normal (i.e. unsigned char images) can now be computed using the ComputeByParts
strategy.

		* src/ComputeByParts.hxx: now handles CV_8U images.
Cleaning the output.

		 * src/ComputeByParts.hxx: Do not write a new line at each iteration.
		 * src/TVL0DecompositionMinimizer.hxx: Do not write messages anymore.
Added arguments to run the non optimal mode.

	  * src/Args.cc: Here.
	  * src/Args.hh: Here.
	  * src/main.cc: Use them.