Synopsys   : FILTER_PRESENT_LIVE(x)

Defined in : /sys/filter_funs.h

Description: This filter returns all elements of an array that are living
             objects and that are in the environment of this_player(). An
             object is living when it has been made living with the efun
             enable_commands. Usually these include all players and NPC's.
Arguments  : object *x - the array with objects to filter.
Returns    : object *  - an array with only living objects that are in the
                         environment of this_player().
