Remove broken link

One of the link containing more information on the function `super()`
was broken. Fixes #1376
Change to epoch_scale earlier for TimeFromEpoch; closes #1122
Add test cases, TimePlotDate correction
Add note to CHANGES.rst
Correction to plot_date doctest in docs/time/index.rst
Try changing empy lines in CHANGES.rst to get rid of
Reword CHANGES.rst to make more obvious to non-intimi what problem was fixed.
Merge pull request #1732 from mhvk/time-fromepoch-scale-conversion

Time fromepoch scale conversion (closes #1122); TimePlotDate correction
Refactor table Column code into a separate file
Merge pull request #1837 from taldcroft/table/factor-col

Refactor table Column code into a separate file
Skip doctests that require a remote server
Specify fixed versions for Matplotlib, Sphinx, and Cython to avoid breaking builds when new versions are released.
Add support for REMOTE flag to doctests.
Document new REMOTE flag in doctests.  Remove out-of-date information
about doctest flags remaining in the output.
Mark some doctests as +REMOTE
Merge pull request #1842 from astrofrog/switch-wheel-servers

Switch wheel server order to use mirror
Remove spurious warning from printwcs, as reported by Maik Riechert on astropy@scipy.org
Add changelog entry.
Merge pull request #40 from mdboom/docs/disable-remote-doctests

Add REMOTE flag to doctests so we can disable tests that require remote data
Added known issue for MAGEIA-2 and 3 install bug