r10913: This patch isn't as big as it looks ...

r10913: This patch isn't as big as it looks ...

most of the changes are fixes to make all the ldb code compile without
warnings on gcc4. Unfortunately That required a lot of casts :-(

I have also added the start of an 'operational' module, which will
replace the timestamp module, plus add support for some other
operational attributes

In ldb_msg_*() I added some new utility functions to make the
operational module sane, and remove the 'ldb' argument from the
ldb_msg_add_*() functions. That argument was only needed back in the
early days of ldb when we didn't use the hierarchical talloc and thus
needed a place to get the allocation function from. Now its just a
pain to pass around everywhere.

Also added a ldb_debug_set() function that calls ldb_debug() plus sets
the result using ldb_set_errstring(). That saves on some awkward
coding in a few places.
(This used to be commit f6818daecca95760c12f79fd307770cbe3346f57)