First implementation of Integer Up/Downsampling
PEP8 corrections
Removing code repetition
Minor refactoring
Downsampling of nD arrays
Padding ndarray with zeros to support downsampling by any integer factor
Added docs, tests for downsample() in skimage.transform._warps
Making code compatible with Python 3
Add _sum_blocks
Cleaning up downsampling for integer factors
Expanding the documentation in transform._warps
Attempt to solve circular import issue
Another attempt at solving circular import issue
Correcting typos
Merge pull request #511 from ankit-maverick/resample

Resampling of nD arrays
Add SART tomography reconstruction to radon_transform.
Make iradon_sart visible in the transform package.
Add tests for transform.iradon_sart.
Implement projection shifts.
Tests for the projection_shifts functionality of iradon_sart.