Delegate user permission to PostgreSQL (closes #18)

If the request is authenticated (with map_key) then we log as the
database owner, otherwise we log as the default user.
The default user is now "publicuser" by default.

Raises dependency on Windshaft to 0.4.9+, to get the grainstore
version allowing override of database username.

Add test for req2params function, particularly authentication,
Add test for authenticated / unauthenticated access

test/support/test_helper.js

@@ -0,0 +1,16 @@
+/**
+ * User: simon
+ * Date: 30/08/2011
+ * Time: 13:52
+ * Desc: Loads test specific variables
+ */
+
+var _ = require('underscore');
+
+// set environment specific variables
+global.settings     = require(__dirname + '/../../config/settings');
+global.environment  = require(__dirname + '/../../config/environments/test');
+_.extend(global.settings, global.environment);
+
+
+