BUG: mantis 1481 - compile KMeansClassification application only if otb is compiled with shark support

ENH: display progress of statistics and histogram computing. Remote empty logging in CheckValidity()

BUG: Fixing bug #1467. No Update() should happen on filters whatsoever, unless you know for sure that the Udpate() call will not load whole image in memory. No local pointers to filters are allowed (because the streaming pipeline disappears at the end of the method)