Use sinogram weights to calculate sino_indicator

Created by: dyang37

Currently unweighted sinogram is used to calculate sino_indicator:

indicator = np.int8(sino > 0.05 * np.mean(np.fabs(sino)))

This would cause problem when "bad" values exist in sino (inf, nan etc.) Usually such case is handled by setting the associated sino weights to be 0 for the "bad" sino values. As a result we should also use weights when calculating the indicator in _sino_indicator function. Maybe a good start point is to try using the weighted sino.