Add support to create TDB databases using the new jenkins hash.

Add support to create TDB databases using the new jenkins hash.

SRVID for the control to attach to a database is used to pass
tdb flags from samba to ctdb when samba attached to a database.
This has been used earlier for TDB_NOSYNC flag.

Add TDB_INCOMPATIBLE_HASH as a supported tdb flag to store in the
SRVID field when attaching to a database.

This allows samba to control if ctdb should create databases using the
new jenkins hash, or using the old hash.
This only affects new databases when they are initially created.
Existing databases remain using the old hash when attached to.