Dataserver bugfixes

Move datastore default paths out of /tmp into /var
Add upstart config files for running HTTPDataStore
Move writeback check inside parseconfig so that config_help reflects /etc/server.local.yaml modifications
Fix auth_tests so they are actually registered
Add test for failure to strip padding that broke HTTPDataStore registration
Change grr_server to allow it to start master/slave dataservers
This seems a bit hackish. If we want to support hostnames here, why don't we do a proper
socket.gethostbyname(self.Address()) == socket.gethostbyname(addr)