Added more tests for NCZLd_channel
Added 3D test case for UpdateXY
Added tests for calculate_xy() in 3D
Simplified tests for UpdateXY() in 3D
Minor cleanup refactoring
Corrected normalize_output() for n dimensions
Corrected input data for calculate_xy() 3D

Now has correct I_norm
Merge pull request #2 from connollyst/multi-channel

multi channel support