Log Message:
py-sqlparse: updated to 0.3.1

Release 0.3.1:

Enhancements
* Add HQL keywords.
* Add support for time zone casts.
* Enhance formatting of AS keyword.
* Stabilize grouping engine when parsing invalid SQL statements.

Bug Fixes
* Fix splitting of SQL with multiple statements inside
  parentheses.
* Correctly identify NULLS FIRST / NULLS LAST as keywords.
* Fix splitting of SQL statements that contain dollar signs in
  identifiers.
* Remove support for parsing double slash comments introduced in
  0.3.0 as it had some side-effects with other dialects and
  doesn't seem to be widely used.
* Restrict detection of alias names to objects that acutally could
  have an alias.
* Fix parsing of date/time literals.
* Fix initialization of TokenList.
* Fix parsing of LIKE.
* Improve parsing of identifiers