a day for debugging

[William la Forge]

Found a bug relating to writing blocks--I had left off the write. :-)

Also fixed a bug in restarts.

Anyway, TransactionContexts.add seems to be working now. Next up is a get method, but there is still a chunk of code missing in KernelHandleElement where we read and deserialize a block. Shouldn't take long to code, though who knows how long it will take to debug. :-)

Things are starting to work anyway, though some chunks of code are missing here and there. Naji has promised to migrate the btree code from AW4 to AW5, and that's one of the more critical pieces. We also need logic for disk space management, handling and throwing collision exceptions, and caching of various sorts. But the end is in sight, and that makes it all worth while.

Hopefully Alex can make some progress on validate, as that is another critical piece.

Bill