ConfigAdmin: Corrected bug and Configuration lock

In some cases, on framework start up with ConfigAdmin and FileInstall,
a ManagedService could be notified twice of with the same configuration.
Count the number of calls to updated() in tests
Added a reload() method to Configuration beans

The configuration requests the persistence service to reload the
storage content and updates its properties accordingly.
Managed services are notified if properties were changed.
Added a shell command config.reload <pid>

Requests a configuration to reload its properties from the persistence service.