More matching tests and associated fixes
docstring fixes and making API public
added matching info to coordinate docs
Added changelog entries for array coordinates and matching
fix for missing scipy check
Changed matching to have 3d and sky versions
correct tests for 3d and sky matching and related fixes
Update docs for 3d/sky changes
added see also to matching methods
force 2d separation to be Angle

that's what it will be one the __getitem__ thing is working, so we
should be compatible now
zap trailing whitespace
Add neutrino mass support.
Add neutrino mass support.
Add unit testing (comparison with mathematica), fix some bugs that revealed.

* Use Mathematica to numerically evaluate the exact expression
  for neutrino mass density, use that to set up some unit tests.
* Fix some minor issues uncovered by those tests, like _nu_y having
  units.
Numpy 1.5 doesn't have count_nonzero

* In FLRW.__init__ np.count_nonzero was used to count the number
  of non-zero neutrino masses.  This doesn't work under numpy 1.4 or 1.5,
  which are still supported by astropy.  Use a try/else against
  AttributeError to use count_nonzero if available, len(nonzero()[0])
  otherwise.
Update import statements in `convolution` docs

(was moved from `nddata` to `convolution`)
Documentation update for neutrino masses, other small fixes.
Add neutrino mass information to __repr__ for cosmology objects.

* Adjust __repr__ for FLRW and all subclasses to output neutrino information.
  For consistency, since %r is used for m_nu (a quantity), also use %r
  for Tcmb0 and H0.
* closes #1302
Correct documentation for return type of absorption distance, make numarray

* This showed up during the rebasing of this branch: the documentation
  for absorption distance was incorrect, saying it returned a quantity.
  Fix the docs, and make the return a np.array rather than a list
  for consistency with all other functions.
* Affects the unit test for absorption distance.
Fix documentation typos pointed out by @nhmc