Implemented net fsmo command for transferring fsmo roles

Implemented net fsmo command for transferring fsmo roles

The command allows the user to transfer a fsmo role to the server to which
the connection is established. Roles can be transferred or seized. By default a
transfer is attempted even if seize option is chosen, as it is dangerous to
seize a role if the current owner is still running.
example use:
net fsmo show --host=hostnameoraddress --username=username --password=password
net fsmo transfer --role=role --host=hostnameoraddress --username=username --password=password
net fsmo seize --role=role --host=hostnameoraddress --username=username --password=password [--force]

Tested against Win2008. Does not work for samba 4 yet as we are missing the GetNCChanges extensions.