PageRDD.slice renamed to joinBySlice.
add leftJoinBySlice to preserve empty join
complete resellerRating example
PageRDD.save renamed to dump to distinguish from saveAs
revise TestPageBuilder to pass
remove #{} validation in action as some input text indeed hold these characters.
add a new action trait 'Container' which holds Loop and If (not implemented yet)
fix a bug where interactions in Loop won't be executed by resolveFinal
Page.doc now become Option[Any] type to hold parsed results other than html.
fix a bug in PageRDD.insertPagination that cause link on the first page to be used repeatedly