Introduce a simple EarthLocation class, subclassed from CartesianPoints
Includes erfa gc2gd so that one can transform XYZ to geodetic
Use location exclusively, deprecating lon and lat (and removing height)
Move conversion of u, v, to "km" to inside the call to erfa
Insert available ellipoids in docstrings by hand
(formatting seems not possible for class methods in python2)
Correct examples in documentation
Move EarthLocation to astropy.coordinates
Correction to time documentation problem from rebase
Time core bugfix for issue 2123
Pickle tests added
Use the `ignored()` context manager where appropriate.  This litte
bugger was just added to the stdlib, and I wanted to bring it into
astropy and use it where appropriate before I forgot it exists, because
I was so enamored with it: http://bugs.python.org/issue15806

As this notebook [1] shows, this is a little slower (about 5x, but on the
order of < 10us) than using try/except directly, so I avoided using it
in some loops.  But elsewhere it's fine to use and a lot nicer looking.
But this is mostly silly and purely optional.

[1] http://nbviewer.ipython.org/urls/gist.github.com/iguananaut/169ba550944e4020dff9/raw/0247ab9190b39b35b14c750aa8fe93d3da1228aa/ignored_performance.ipynb
Testing for different pickling protocols
Correct path in time.__doc__, and add entry to CHANGES.rst
Updated docstring to reflect the release of Python 3.4
Let EarthLocation use structured array; update erfa, time, tests
Tests for EarthLocation
Further tests, correction of test for view for slicing
Use fake np.isclose for numpy<1.7
remove pickle file test
Add CHANGES entry
Added gaussian absorption model.