Refresh All not disabled when no connection is selected

[StreckerCM]

It is possible to select Refresh All on the Hierarchy tab when there is no connection selected. When this is done the cursor changes to a wait cursor and will stay that way indefinitely or until a connection is selected. This could cause a user to mistakenly think that the application or server is not responding.

Steps to Reproduce:

1. Open PDS WITSML Studio
2. Switch to the Hierarchy tab without making any changes on the settings tab
3. right click on the hierarchy browser
4. choose Refresh All

Work Around:
User can switch back to the Settings tab and select a connection. Then switch back to the Hierarchy tab and the refresh will execute.