- Using 'out' rather than 'output' for in-place operations to conform to numpy convention
- Added a kernels.Kernel base-class implementing cdf, pm1, pm2, fft and dct in term of the pdf
- Corrected all the kernels, both Python and Cython
- Added and restructure kernel tests
- Restructured KDE tests.
- Moved TransformKDE to the kde_methods
- Updated tutorial
- Added decorators for 1 argument numpy transformations (i.e. functions working
on arrays and returning an array of same shape as the input)