Add fiexed-length column serde

Hive does not support setting the column delimiter as a space. Some systems require storing files in fixed-length format. I am thinking that maybe we can add this feature. I can submit the code, and create tables like this.

```sql

CREATE TABLE fixed_length_table (
  column1 STRING,
  column2 STRING,
  column3 STRING
)
ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.fixed.FixedLengthTextSerDe'
WITH SERDEPROPERTIES (
  "field.lengths"="10,5,8"
)
STORED AS TEXTFILE;

```