[SQL] SPARK-1964 Add timestamp to hive metastore type parser.

Author: Michael Armbrust <michael@databricks.com>

Closes #913 from marmbrus/timestampMetastore and squashes the following commits:

8e0154f [Michael Armbrust] Add timestamp to hive metastore type parser.

(cherry picked from commit 1a0da0ec5799f3226ce238cac03f53fa4f7c9326)
Signed-off-by: Reynold Xin <rxin@apache.org>