Important fix for critical bug introduced in SQL syntax highlighting in implementation for #190

For the changes for #190 I have done a major bug when copying the regex for multi line comments in SQL from Java syntax. I only copied the regex without assigning it to 'comment', so the hole JavaScript syntax of the SQL highlighting definition is now broken.

Please merge this pull request into master to get a bugfix. Thank you and sorry for introducing this trouble!

Cheers
Holger