bsddbtxn.py -- Wrapper for BSDDB DBTxn to support context manager protocol
txn.py -- GrampsDbTxn class to manage atomic transactions
write.py -- GrampsDbWrite class for read/write databases
read.py -- GrampsDbRead class for read-only databases
undoredo.py -- GrampsDbUndo class to manage the undo database
upgrade.py -- Helper module for upgrading a database at open time
svn: r13078