Merge pull request #1 from jonathan-taylor/master

Major refactoring -- atoms test all passing
Merge remote-tracking branch 'jonathan/master' into main-master

* jonathan/master: (94 commits)
  docstring edits
  install directions
  fixing iterations in FISTA
  removing unused offset_map
  removed all copy from affine_transform
  set copy=False everywhere
  making todense public
  some fixes to tests
  changing inv_step to step
  the adjoint still needs to be applied
  making reshape optional
  trying to make the fit method more modular
  changing variable names in guts of FISTA
  partial_svd using warm_start now
  removing linear_fractional
  improving nesta
  adding a product transform, changed dual to output, primal to input; adding api
  latexify docstrings
  adding docstrings to methods of atoms
  docstring of quadratic property
  ...
RF: remove use of numpy distutils

Refactor setup.py not to use numpy distutils.
Add Cython extensions to allow copying of .c files into sdist.
Add nibabel extension to check dependencies.
Remove numpy.distutils setup.py files.
.gitignore built C files
BF: add fake_pyrex module for setuptools / Cython

I can't remember if this is needed still, but just in case.
RF: move code directory to top level

Move code directory to top level for more standard layout.
Merge pull request #3 from matthew-brett/setup-and-code-dir

RF: setup.py changes; move code directory