Use an ''eager'' cursor for PySqlite.
Pre-fetching all the rows seems to be a robust way to avoid the dreaded ''Database is locked'' error, which seems to be gone for good.
Thanks to Gerhard Haering who wrote the !EagerCursor class (see pysqlite🎫233).
Closes #3446.
Authored by: cboos 2009-09-10
Parent: [r8588]
Child: [r8590]
