DOC: Update docs to 2.0 and scipy 0.13.0

Fixes #383
DOC: Remove the concept of sparse/dense
DOC: Remove sparse/dense in biom_conversion.rst
DOC: Remov docs about the backends
DOC: Remove sparse/dense descriptions
DOC: Remove reference to table factory and types

Fixes #383
DOC: Add mention of h5py to doc/index.rst

Thanks @wasade!
DOC: Add autoclass directive for Table class
DOC: Update required numpy version to 1.7.0
Merge pull request #388 from ElDeveloper/issue-383

DOC/ENH: Update docs ⚠️ not ready for merge⚠️