don't lock the META table in verifyMetaLocked(), since we're just going to throw an exception if it wasn't locked already

some minor renaming and code movement around table locking to make it easier for me to follow the code

Sequences of temporary tables (auto-increment or identity columns) were persisted unnecessarily in the database file, and were not removed when re-opening the database.

Rename "updateOrInsert" back to "update", because it could also be "delete", or changing a setting, or running system command. "update" and "query" are the same terms used as in "Statement.executeUpdate" and "Statement.executeQuery".

Sequences of temporary tables (auto-increment or identity columns) were persisted unnecessarily in the database file, and were not removed when re-opening the database.

change method name in CommandContainer, update() -> updateOrInsert(), to more accurately reflect it's purpose.

Fix bug in changing encrypted DB password that kept the file handle open when the wrong password was supplied. (test case from Jens Hohmuth).

MVStore: an IndexOutOfBoundsException could sometimes occur MVMap.openVersion when concurrently accessing the store. 

and which servers that are available. (patch from  Nikolaj Fogh)