Add flat prior option to binom_conf_interval.  Fix bugs with scalars.

* Add flat prior option to binom_conf_interval and binned_binom_proportion
* Fix bug where jeffreys prior crashed when given scalar values of k.
* Added unit test for flat prior and for scalar jeffreys prior.
* Update docs and put in 0.4 changelog
Fix typo (fucntion)
Comments from @kbarbary

* Fix docs
* Try to return input shape more faithfully.  Add some unit tests
  of that behavior.
Change the way shapes are handled in binom_conf_interval

* Rather than explicitly reshape the output, treat scalars
  as a special case and let the ufuncs deal with broadcasting.
  Doesn't seem to change any aspect of the output.
Spelling correction for UNIT_NOT_INITIALISED, PEP8 changes
(found by emacs showing nice pink lines for mistakes)
Add test cases for uninitialized unit
Merge pull request #2257 from mhvk/quantity-remove-the-pink

Quantity spelling correction for UNIT_NOT_INITIALISED, PEP8 changes
Update index.rst

Fixed typo.
Fixed Gaussian2D model for cov_matrix input
Added change log entry for #2199
Added regression test for #2199
Changed Gaussian2D model rotation to increase counterclockwise
Updated regression tests for #2199
Updated documentation for Gausian2D model
Merge pull request #2263 from larrybradley/patch-5

Update index.rst
Updated change log entry for #2199
Updated docs to display the covariance matrix as a matrix
Explicitly raise NotImplementedError for _repr_latex on Quantity arrays
Merge pull request #2157 from aconley/binom_flat

Add flat prior option to binom_conf_interval.  Fix bugs with scalars.
Added HTML reader to io.ascii