Revert "fix middleware classes"

This reverts commit 7a60f96f904892e1e185382c950201e20b67e507.
Revert "fix INSTALLED_APPS"

This reverts commit 00031709b39ad647a5476c4d770c273c5f9d56c3.

Conflicts:
	mozillians/settings/base.py
[fix bug 689167] Re-enable CSP.
Merge pull request #645 from glogiotatidis/csp-again

Csp again