Add the doc build tools

tools/build_docs.sh generates the devstack.org website from the static
pages and generated pages created by running shocco against a DevStack
checkout.

Note that while this is the complete auto page generation of the
devstack.org site, pushing the content back to GitHub is limited
to those with push access to the current repo.

Partial-bug 1235626

Change-Id: I61dc3d56e4a4832a9ddd1904dd8af65c15a17e50
Set keystone.conf to mode 0600

Fixes CVE-2013-1977
DevStack is not meant to be the example of a secure OpenStack
installation, however we should get these things right for testing.

Fixed bug: 1168252

Change-Id: Idd13b7a58e257565052c54f72c65d8dceb23f27a
Merge branch 'docs-shocco' into dt-test
Merge branch 'CVE-2013-1977' into dt-test