ldb: Release ldb 2.0.2

ldb: Release ldb 2.0.2

 * Checking pack format is version 1 and erroring if not (will change soon)
 * Pack format routines for unpack and pack version 2 (but not used)
 * Test fixes for issues caused by upcoming repack functionality for upgrade
 * Making ldbdump print out pack format info and keys so we have low level visibility for testing in python

Signed-off-by: Aaron Haslett <aaronhaslett@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Gary Lockyer <gary@catalyst.net.nz>