Earlier INSERT...ON DUPLICATE KEY UPDATE work.
Huge refactoring.  Always heavyweight lock first.

It seems preferable to have a good protocol for doing locking/unlocking of
values.  HW lock first, then buffer lock seems like a good one.
Better normal inserter assertion
Fixes
Fix 02 compiler warnings
Fix bug for regular insertoin
moveright for reg insertion fix

We can have moveright for pagesplits during regular insertion.  That's fine, I
think, just make sure that new page isn't locked.
Comment tweak, trade-off
Refine
comment
Non-spec inserters must retry too, sometimes
Re-consider non-spec retry comments

It's probably just that an xact that set the flag aborted, so leave open the
possibility that we don't really have to do this.
Think about aborted xacts
Minor tweak
Minor tweak
Attempt to lock page not buf. Still one bug.
Fix silly bug
Clean-up
Remove unneeded variable
Fix bug

restart at smarter point on page split.