Add Option: ClassifiedFee

Add option to set minimum fee for publishing classifieds. Many viewers have a
  hard coded minimum of 50, which makes publishing classifieds fail where grids
  have no economy. This allows the grid to set the minimum fee to a suitable
  value for their operation.

  The option is located in the [LoginService] section and defaults to 0. The
  value is sent as "classified_fee" in the login response.

bin/config-include/StandaloneCommon.ini.example

@@ -115,6 +115,9 @@
     ;; Ask co-operative viewers to use a different currency name
     ;Currency = ""
 
+    ;; Set minimum fee to publish classified
+    ; ClassifiedFee = 0
+
     ;; Regular expressions for controlling which client versions are accepted/denied.
     ;; An empty string means nothing is checked.
     ;;