Merge pull request #300 from sqweek/issue184

Fix inconsistent tx state with database/sql.

sqlite3.go

@@ -296,6 +296,12 @@ func (ai *aggInfo) Done(ctx *C.sqlite3_context) {
 // Commit transaction.
 func (tx *SQLiteTx) Commit() error {
 	_, err := tx.c.exec("COMMIT")
+	if err != nil && err.(Error).Code == C.SQLITE_BUSY {
+		// sqlite3 will leave the transaction open in this scenario.
+		// However, database/sql considers the transaction complete once we
+		// return from Commit() - we must clean up to honour its semantics.
+		tx.c.exec("ROLLBACK")
+	}
 	return err
 }