Switch to using `FETCH()` and `STORE()` to get and set DBI attributes where possible. The primary reason is to avoid death during global destruction, when the DBI's `tie`d interface can sometimes be pulled out from under us. Switched to the OO interface througout to be consistent.
…the proxy class used by `with()`.
* `svp()` no longer throws an exception whe used with an RDBMS that doesn't support savepoints. In such situations, savepoints are treated as a no-op, and thus the transactional behavior of `svp()` becomes the same as `txn()`. * Moved up the discussion of calling `svp()` outside of a transaction in the documentation.
…svp()` are no longer passed on to the execution of the block, since they are immediately available to the closure, anyway. This simplifies things for integrated exception handling.