Enable authentication with smog!

2 updates here:
 - if user entered a password, try to authenticate against "admin" db first then drop back to desired database.
 - if any admin operation fails (in the case of a non-admin user), keep going; don't assume we should throw an error here.

lib/services/admin.coffee

@@ -5,26 +5,34 @@ module.exports = (cb, socket) ->
   db = cb.socket.mongo.database
   admin = db.admin
 
-  db.collectionNames (err, r) ->
-    return cb err.message if err?
-    out.collections = r
+  # authenticate against "admin" db first, then go back to original.
+  if db._dbconn.options.password
+    dbOrig = db._dbconn.databaseName
+    db._dbconn.databaseName = "admin"
+    db.open  (err, r) ->
+      db._dbconn.databaseName = dbOrig
+      db.open (err, r) ->
 
-    admin.serverStatus (err, r) ->
-      return cb err.message if err?
-      out.serverStatus = r
-
-      admin.buildInfo (err, r) ->
-        return cb err.message if err?
-        out.buildInfo = r
-
-        admin.profilingLevel (err, r) ->
+        db.collectionNames (err, r) ->
           return cb err.message if err?
-          out.profilingLevel = r
-
-          admin.profilingInfo (err, r) ->
-            return cb err.message if err?
-            out.profilingInfo = r
-
-            admin.replSetGetStatus (err, r) ->
-              out.replSetGetStatus = r unless err?
-              return cb null, out
+          out.collections = r
+
+          admin.serverStatus (err, r) ->
+            # return cb err.message if err?
+            out.serverStatus = r unless err?
+
+            admin.buildInfo (err, r) ->
+              # return cb err.message if err?
+              out.buildInfo = r unless err?
+
+              admin.profilingLevel (err, r) ->
+                # return cb err.message if err?
+                out.profilingLevel = r unless err?
+
+                admin.profilingInfo (err, r) ->
+                  # return cb err.message if err?
+                  out.profilingInfo = r unless err?
+
+                  admin.replSetGetStatus (err, r) ->
+                    out.replSetGetStatus = r unless err?
+                    return cb null, out