add central function to list placeholder and clean an attribute name so that parsePlaceHolders won't choke on them
add central function to list placeholder and clean an attribute name so that parsePlaceHolders won't choke on them

tarekdj/phplist3,mariez/phplist3,samtuke/phplist3,samtuke/phplist3,bramley/phplist3,phpList/phplist3,phpList/phplist3,phpList/phplist3,phpList/phplist3,byronjumbo/phplist3,samtuke/phplist3,mariez/phplist3,danwaterloo/phplist3,bramley/phplist3,mariez/phplist3,tarekdj/phplist3,tarekdj/phplist3,tarekdj/phplist3,mariez/phplist3,danwaterloo/phplist3,danwaterloo/phplist3,danwaterloo/phplist3,danwaterloo/phplist3,samtuke/phplist3,phpList/phplist3,bramley/phplist3,samtuke/phplist3,byronjumbo/phplist3,bramley/phplist3,mariez/phplist3,byronjumbo/phplist3,bramley/phplist3,byronjumbo/phplist3,byronjumbo/phplist3,tarekdj/phplist3