Merge pull request mybatis#1110 from diribet/batch-executor-fix

In BatchExecutor, close each statement right after it is executed.
Although proper flushing should be sufficient in most cases, this could lower the possibility of an error like "ORA-01000: maximum open cursors exceeded".

Author: harawata

src/main/java/org/apache/ibatis/executor/BatchExecutor.java

@@ -131,6 +131,7 @@ public List<BatchResult> doFlushStatements(boolean isRollback) throws SQLExcepti
               keyGenerator.processAfter(this, ms, stmt, parameter);
             }
           }
+          closeStatement(stmt);
         } catch (BatchUpdateException e) {
           StringBuilder message = new StringBuilder();
           message.append(batchResult.getMappedStatement().getId())