Added missing functionality in OrganizedFastMesh

There were still some TODOs in the code. I just added this missing functionality in the course of cleaning up all my old code and pushing it (part after part) into the PCL. New functionality:
* Now allows for specifying a (optionally distance dependent) distance tolerance for filtering shadowed edges 8 (shadowed edges with a length within the tolerance are assumed to be caused by local noise, and not filtered out).
* Now allows for specifying a viewpoint other than the default (0, 0, 0).
* Removed (marked as deprecated) the old _unused_ function to specify a maximum edge length.  
For sure not the last change to this file.