added category id filter to functions.php, set up list view apply the filter

added category id filter to functions.php, set up list view apply the filter
to check for the ids in the category array

placed filter in functions.php that will allow the list view template in
the theme to have access to the set of manufacturer ids and compare them
to the categories in the category array supplied by the list model. this
is to build out of the list of manufacturers and brands for the search
widget