Fix setup.

Fix setup script.

Refactor ffs_shift.

Add convolution.

Fix cupy ifftcall. (#26)

Clean up read the docs config.

* Add multi-dimensional transforms.

* Overhaul documentation.
* Add profiling scripts.
* Add test suite.

[Dist] Make pip-installable (/w --editable flag).

[Doc] Provide conda installation instructions.