shadow_copy2: create structure to store module specific information

shadow_copy2: create structure to store module specific information

Create a separate structure to store module specific information. Currently
only config values are saved. As of now there is no cleaner way to store run-time
information or other module specific information in shadow_copy2 module.

Therefore created a new structure to store all module specific information
including config.

Signed-off-by: Rajesh Joseph <rjoseph@redhat.com>
Reviewed-by: Uri Simchoni <uri@samba.org>
Reviewed-by: Michael Adam <obnox@samba.org>