added RandomForest constructor argument 'label_count'
vigranumpy RandomForest constructor: provide the list of labels rather than their number
vigranumpy.filters.distanceTransform3D(): added support for anisotropic data (fixes #139)
added NaN handling to RandomForest predict functions
added anisotropic distance transform for 2D
minor HDF5 fixes (reports by St. Meister und J.M. Gottfried)
increased tolerance for a few tests (reports by V. Hilsenstein and A. Metzler)
HDF5: enforce chunking when compression is requested
HDF5: make sure chunk size doesn't exceed shape
	Merge branch 'master' into coordinate_extractor