Implemented Module enable/disable setting from configuration.

Implemented dependencies checking to set CMS_MODULE.is_enabled.
Implemented the persistence of CMS_USER.roles

examples/demo/site/config/cms.ini

@@ -12,3 +12,14 @@ theme=bootstrap
 smtp=localhost:25
 #sendmail=/usr/bin/sendmail
 #output=@stderr
+
+[modules]
+*=off
+auth=on
+basic_auth=on
+blog=on
+debug=on
+demo=on
+node=on
+oauth20=on
+openid=on