s3:winbind add timeouts to winbind cache

s3:winbind add timeouts to winbind cache

This adds a timeout value to cache entries and the NDR records
in the winbind cache.

The previous approach of just comparing the sequence number has some issues,
e.g. when retrying a wbinfo -n operation for a user in a not yet trusted
domain was always failing even after the trusted domain was added.

The new approach compares sequence number and timeout value to
determine if a cache entry is still valid or not.

I increased the cache version number so an old cache will be wiped
automatically after upgrade.