WRG: fix for variable 'prolateCoefficients' is not needed and will not be emitted [-Wunneeded-internal-declaration]

BUG: dynamic_cast fails when image is not of type OutputImageType. Replacing the GetProjectionRef() call since it is the only one requiring the dynamic cast

BUG: OGRIOHelper needs to create Memory datasource, so OGRRegisterAll need to be called. this fixes test otbVectorDataToLabelImageFilterWithoutReader

BUG: OGR SpatialReference is first morphed to ESRI when using segmentation filter with .shp output. Thus comparison mst be added in Initialize method. Mantis ref #567

     Used in inherited class for example to implement a simpler
     GetPixelDescription method.