Remove postgresql config

Not using it anymore. Sessions are in cookies and other tmp data in
redis
Remove OAuth code

This just cannot work with our LDAP security model...
Merge branch 'no-oauth'

Conflicts:
	debian.default/control
	lib/puavo/authentication.rb
web: Remove ActiveRecord

http://stackoverflow.com/a/2212867/153718

Not using it. No need to require or configure it.
rest: Remove pg from rest Gemfile.lock
web: better monkeypatch for schema cache
Merge branch 'cleanup'