Adding ability to include python/numpy modules
Adding python framework and python test framework

Addresses build for python, without yet building anything.
Build should happen such that the python package cna be imported using the right PYTHONPATH leading
to the build directory.
Closes #10, #11
Bindings for visibility

* Reads visibility from disk
* Bindings are generated using cython
* Closes #14
Sanitized CMake for cython modules and python files
Set image pointer to pixel NULL after deallocation
Adds bindings for images

* Closes #15
Set deallocated pointers to NULL
Sparse matrix bindings

Goes part way to resolving issue #17
Split sparse matrix into header and implementation

* Moved the python testing functions to their own cython file.
  They will not be included in the distributed package this way.
* Rationalized copying files as targets via new add_copy_files function.
* Rationalized add_cython_files to accept arguments and put cython stuff into separate build file.
Wrapper for dataframe to visibility

Separated visibility into header and implementation files.
Corrects framework detection on MacOSX

CMake often detects python interpreters and python libraries/headers from different framework.
This fix should make it easier to align the libraries/headers onto the detected interpreter.
Move purify.*.pxd header creation to root package

Makes it possible for  different submodules to import each other.
Adding bindings for kernel creations

* Should potentially create a hardening test for the interpolation kernel.
  Or try to understand what it does...
* Closes #17
* No test for interpolation kernel #18.
Corrects cython dependencies
Adding FFTW bindings

* Closes #19
Adding sopt_sara_param bindings

Closes #22
sopt bindings: sara_analysisop, sara_synthesisop

BasisFunctions class is iterable/getitem-able. It contains named tuples with informations regarding
the wavelets in the basis sets.
Two member methods create bindings for sara_analysisop and sara_synthesisop.
Move functors.pyx to measurements.pyx
Add missing tests to ctest framework
Creating scipy sparse matrix does not copy data

Turns out that scipy does not copy the input arrays when creating a sparse matrix explicitely (e.g.
from compressed values and indices). This means it wraps around the C arrays quite easily.

Changed docstring and test to reflect that.
However, current API is not safe, since the C memory is not handled by the python API. This can
result in numpy arrays with dangling data pointers. We should create a cython to explicitely manage
_SparseMatRow's memory.