[MANIFEST.in] include LICENSE in sdist
[doc] mention self tests in "installation.rst"
[doc] add section "How to use this documentation"

o remove "reference_guide.rst" --> merge into "index.rst"
[doc] resolve sphinx warnings concerning cython functions

o modify decorator "inherit_docstring" --> append doctring from base class
  instead of overwriting it
o this keeps the call signature cython writes into the docstring
o with the call signature in the docstring, sphinx can consistently build
[scripts] move scripts into Makefile targets
[examples] add example MCMC+VB
[density] Fix gauss, student's t for 1D proposal
[mix_adapt/r_value] update doc string
[mix_adapt/variational] add todo: expose responsibilities
[tools/convergence] Add to doc
[examples] Change uniting_markov_chains_and_variational_bayes

o target = mixture of three student's t
o adjusted lots of comments
o add perpl. and ess at the end
[density] Unit test for local* in 1D
[tools/parallel_sampler] clean up

o remove signature from docstring
o remove try-except import --> not needed when the test runs with nose