This one was already merged into release-16.09, so let's not have the
stable branch is ahead of master and confuse things. In addition to
that, currently we have an odd situation that master has less things
actually finished building than in staging.
Conflicts:
pkgs/data/documentation/man-pages/default.nix
The previous commit revealed that Python wasn't actually using
Berkeley DB; it only had it in its closure due to the build-time flag
dump in Makefile and _sysconfigdata.py. When Python detects both GNU
gdbm and Berkeley DB at build time, it will use the former.
This reduces Python's closure size from 200 MiB to 129 MiB. Even
better would be to get move tkinter to a separate output or package
(since that would get rid of all X11 stuff), but that's a bit harder.