Motivation:
typically, every time when file's open/lock/layout state id is used to
change file's state, the sequence number is incremented. Thus newly
created stateid should have sequence zero, as it will be bumped during
processing. As currently sequence number initialized with one (1), fresh
created lock and layout state ids have sequence 2 when sent to the
clients.

Modification:
Initialize sequence number of newly created state ids with zero.
Increment open state id's sequence number for all state ids.

Result:
better spec compliance, as lock and layout state ids will start with
sequence 1.

Acked-by: Jürgen Starek
Target: master, 0.19