Add option to clone StatusDB

I've modified the couchdb_replication script that I made to configure continuous replication and added an option to clone completely the database, as we discussed. 

I've also added an option to load the credentials from a configuration file, otherwise they will be visible, as you have to put them in the http requests. In summary, the new option does:

* Removes all databases from destination.
* Creates all databases present in source into destination, copy the data and the permissions.