handle varied letter casing of current_timestamp and optional parens

Author: Drew Repasky

mysql2sqlite

@@ -183,7 +183,8 @@ aInc == 1 && /PRIMARY KEY|primary key/ { next }
   #   BEGIN
   #   UPDATE Package SET LastUpdate = CURRENT_TIMESTAMP WHERE ActionId = old.ActionId;
   #   END
-  gsub( /ON UPDATE CURRENT_TIMESTAMP|on update current_timestamp/, "" )
+  gsub( /ON UPDATE (CURRENT_TIMESTAMP|current_timestamp)(\(\))?/, "" )
+  gsub( /(DEFAULT|default) (CURRENT_TIMESTAMP|current_timestamp)(\(\))?/, "DEFAULT current_timestamp")
   gsub( /(COLLATE|collate) [^ ]+ /, "" )
   gsub( /(ENUM|enum)[^)]+\)/, "text " )
   gsub( /(SET|set)\([^)]+\)/, "text " )