Merge pull request #2310 from mdboom/tests/how-to-skip-all-doctests

Include an example of how to skip all doctests in a module
sip_pix2foc should subtract crpix and the end, and sip_foc2pix should do
the inverse.
Add an example.  Closes #1957 and supersedes #1959.
Workaround for #1953.  The BinTableHDU constructor handles data that is not already in FITS native format poorly.  FITS_rec.from_columns, on the other hand, does.  So go through that first.
some cleanup in io/ascii/tests

Some of the tests still had import ... as asciitable as a heritage
from the old asciitable package. Similarly, there was some
require_numpy from times when asciitable worked without numpy.
Nothing important, but hey, why not fix that when I am sitting at a
bus station anyway.
Merge pull request #2346 from mhvk/time-location-doc-touchup

EarthLocation touchup's, mostly in documentation
Merge pull request #2365 from hamogu/cleanupascii

Change "io.ascii as asciitable" imports to ascii
io.ascii.ui: typo in Error mesage?

I think this is just a typo. If not, then I don't understand what it means.
fix sphinx warning

sphinx labels have to come *immediately* before the section heading.
__repr__ method in Table now also returns the units

updated doctests (for __repr__ table)

updated doctests (for __repr__ table), corrected

modifying table_repr_method

show units only when atleast one column is not None. + doctests updated.

show units only when atleast one column not None. + doctests updated.

removed quotes from 'None'.

some code standardization

added test for repr method, updated changes.rst

added doctest for repr method, updated chages.rst
Added support for inputting units
Added test for units and corresponding data file
Removed unnecessary statement
Added support for inputting column description as well
Included test file in setup_package
Changed SExtractor test to include a description check
Adding autoclass_content=both to sphinx conf
Slight improvements to model string formatting

This deduplicates a lot of `__repr__` and `__str__` code for Model
and its subclasses, so there is more consistency between different
Model classes in what their `__repr__` and `__str__` output.
Also made some slight improvements to the previous output formats.
I still don't claim this to be perfect, but it's a step in a better
direction.  In particular I think displaying the different parameter
sets as a table is nice.

These changes are a prerequisite to another, potentially more
interesting change.
trying to allow way to pass in non-local packages
fix autmodapi to properly do options for automodsumm