BLD : clean up setup.py

 - make sure all parent directories exist
 - make sure yaml gets install if not using develop
MNT : patching up of api changes in metadataStore
ENH : support more of the numpydoc spec

 - deal with enums specified in docstrings
 - deal with doubled up documentation
 - deal with (N, ..) array_like docstrings
ENH : proof of concept wrapping convolve