ctdb: Rev 51

[Peter Somogyi]

Hi Tridge,

I've modified your code as one possible solution in my rev51. Please digest & 
understand it carefully.

Other possible solution is hiding ib speciality regarding ibw_alloc_send_buf, 
however then we need an additional memdup.
(Note: I've already been hiding that (void *)key stuff from you - assuming 
"normal" usage.)

Please decide which way to proceed (you accept rev51 _or_ I can implement it 
via memdup penalty.)

Peter