Column "locked" is not found by case-sensitive databases (patch is attached)

Hi Nathan,

since Liquibase 2.0 RC6 we get the following error when updating our databases:
  Error executing SQL SELECT “locked” FROM “DATABASECHANGELOGLOCK” WHERE “ID”=1
 

Background:
We use our databases in a case-sensitive way to improve readability of table names, constraint names, and so on.

The correct SQL statement must therefore look like:
  SELECT “LOCKED” FROM “DATABASECHANGELOGLOCK” WHERE “ID”=1
 

The appended patch.txt solves this problem.
We have tested this patch successfully with all of our databases: DB2, H2, MSSQL, Oracle, PostgreSQL.

Perhaps this is also a solution of the following bug report: http://liquibase.jira.com/browse/CORE-506
(concerns the comment by Oliver Libutzki on 05/Oct/10 7:36 AM.)

Kind regards,
Markus M�ller

I applied it, it looks good.  Thanks

Nathan