r7828: Although there is still plenty to do, ldb_sqlite3 now passes the set of tests

r7828: Although there is still plenty to do, ldb_sqlite3 now passes the set of tests
in tests/test-sqlite3.sh (tests/test-generic.sh).

There are lots of optimizations still TBD, and some things are REALLY slow
right now (e.g. each add() operation takes 1/3 - 1/2 second) but it's ready for
interested parties to poke it and prod it and see how (un)reasonable it is.
Play away.

Still to be implemented or improved:
 - tdb specials (@MODULES, @SUBCLASSES, etc.)
 - all DNs are case-folded in their entirty right now (since doing otherwise
   would require @ATTRIBUTES to be implemented)
 - speed improvements and optimizations.  I am quite confident that the
   excessively slow add() operation can be much improved, and other areas
   can be somewhat improved.