Add changelog entry for #2609
Merge pull request #2612 from vlakoff/documentation

Add changelog entries for #2609
Code cleanup in db->order_by()
Adjust a few phpdoc in query builder code
Merge pull request #2626 from vlakoff/develop-2

Code cleanup in db->order_by()
Merge pull request #2627 from vlakoff/develop-3

Adjust a few phpdoc in query builder code