also advance to end of array for object-based observers

This is a backport to the 2.5 branch, see the following:

https://github.com/joomla/joomla-cms/commit/791f5612ac7305f94789411f4c3fc459c91077a5
The property "catslug" missing on view category.
 JUserHelper getProfile method should be static  

http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=33717&start=0
Merge pull request #3505 from danslo/patch-1

also advance to end of array for object-based observers
Merge pull request #3514 from ITPrism/missed-catslug-property

The property "catslug" missing on view category.
Merge pull request #3577 from vdespa/patch-10

[#33717] JUserHelper getProfile method should be static