Merge in Views Arg Sort module

This issue is for merging in the functionality of
http://drupal.org/project/views_argsort
#852006: Same functionality in Views Arguments Extras

I will provide a patch.

The only thing unresolved for me is: does your module support pgsql for arg sorting? If not, then there will be no functionality loss. If yes, then we would consider a switch statement based on what database is being used and have support for both handlers.