make the subscribe messages a bit more verbose

locale/en-US/preferences.properties

@@ -1,10 +1,10 @@
 # Status messages when subscribing
 messageConnecting       = Connecting...
-messageDuplicate        = You have already subscribed.
-messageInvalid          = The location is blank or invalid.
-messageInvalidLoginData = The username or password is blank or invalid.
-messageConnectionError  = Connection error or location cannot be found.
+messageDuplicate        = You are already subscribed to this message source.
+messageInvalid          = The location you entered is not recognizable.
+messageInvalidLoginData = You have to enter a username and password to subscribe to this message source.
+messageConnectionError  = There was an error connecting to this message source.  Please check the location and try again.
 messagePassword         = Your credentials were not accepted.  Please check your username and password and try again.
 messageConnected        = Connected.
 messageGettingMessages  = Getting messages...
-messageSuccess          = You have successfully subscribed.
+messageSuccess          = You have successfully subscribed to this message source.