[matplotlib-devel] whats_new and api_changes

Fellow developers,

I know we are now encouraged when writing a PR not to alter
doc/users/whats_new.rst and doc/api/api_changes.rst directly, but rather to
create files in the doc/users/whats_new and doc/api/api_changes directories
instead.  When building the master branch docs I was expecting the contents
of these new files to be automagically incorporated in the appropriate doc
sections, but this does not happen on my development system (ubuntu 14.04,
python 2.7, sphinx 1.2.2).

I figure either I am doing something wrong, or this is a bug, or there is
manual process at release time to cut and paste the new files into the
parent files.  Which is it?

Ian