Bug fixes and improvements

- Bugfix: The configuration collection can not have a key for the
values.
- Bugfix: It was possible, that the shutdown handler list was init to
late.
+ ConfigDB: It is now possible to write and therefore to change a
configuration value.
+ Added a few more message names for the logger.

Log/Meta/MessageNames.go

@@ -31,4 +31,8 @@ const (
 	MessageNamePRODUCER      = `Producer`
 	MessageNameCONSUMER      = `Consumer`
 	MessageNamePASSWORD      = `Password`
+	MessageNamePARSE         = `Parse`
+	MessageNameUSER          = `User`
+	MessageNameREQUEST       = `Request`
+	MessageNameRESPONSE      = `Response`
 )