Memory management issue

[jmirabel]

Servant keys should not be the storage pointer.

This pointer may be deleted and the same address could be given to another object. In this case, the server will think it already has a servant for this pointer and will return the old servant, which is wrong.

Note that this only happens when persistent storage is set to false. A possible fix is to remove the servant from the server map when persistent storage is disabled.

[jmirabel]

Related to agimus/agimus-hpp#14