*Possible* fix for #2318.  Not sure if this will fix @cdeil's specific issue, but it *did* fix the issue for me running on my laptop on the institute network.
Allow mask to be set to anything that can be converted to a numpy bool array
Allow flags to be set with array-like in addition to array or FlagCollection
Convert mask and flags input to ndarray
Changelog entry
Use np.intp_t for indices
Check for and prevent initialization of NDData with Quantity

Closes #2374, though admittedly in an unsatisfactory way.
Add changelog entry
Fix masking in arithmetic

Closes #2403
Add changelog entry
correct numerous errors in documentation
Install wcs headers when using bundled wcslib only
Update changelog for #2536
Install config file.
Speedup of initialization for cosmology objects

* Speed up initialization by about a factor of 100 by pre-computing
  some unit conversion quantities.  It turns out this was the
  dominant cost, particularly the call to const.G.cgs.
* import astropy.cosmology time falls by about 50%
* Passes all unit tests
* Closes #2479 (sorta; some more sophisticated options were
  also discussed for that, and this just does the simple bit).
PEP8ify cosmology.core
Performance improvements for astropy.units

- For compose, the set of destination units are prefiltered to only
  include units that have bases in common with "self".  This cuts down
  on the search space considerably in most cases.

- Inline some delegation functions.

- Replace 2 isinstance calls with 1

- Cache the hash of composite units, which can be expensive to compute.
Add CHANGES entry.
Allow NDData and uncertainty to be set with Quantity
Fixes for @nhmc comments, more pep8ification.