feature request: auto savepoint for interactive psql when in transaction.

I ruined a 5 hour UPDATE by typoing a table name on a SELECT to verify
the update worked. I suppose I have no one else to blame, but it was
really frustrating, to say the least. I assume this has happened to
others as well.

I only later found out about SAVEPOINT, which I immediately ran the
next time I attempted the huge update.

psql console, while in a transaction, and while in interactive mode,
should savepoint for me.

—Will

bqjezaraxa=# select count(*) from transactions where log='';
ERROR:  relation "transactions" does not exist

bqjezaraxa=# select count(*) from transfers where log='';
ERROR:  current transaction is aborted, commands ignored until end of
transaction block

bqjezaraxa=# oh damn it ;
ERROR:  syntax error at or near "oh"
LINE 1: oh damn it;