dfm_gen & merger: Changed word cutoff point to be a general setting in dfm_gen. Cuts off at the last [.?!] before the cutoff point (so returns documents at a sentence, shorter than cutoff).
#' @param cutoff_lower Cutoff value for minimum cosine similarity above which documents are considered duplicates (inclusive)
#' @param cutoff_upper Cutoff value for maximum cosine similarity, above which documents are not considered duplicates (for debugging and manual parameter tuning, inclusive)
#' @param es_pwd Password for Elasticsearch read access
#' @param words Document cutoff point in number of words. Documents are cut off at the last [.?!] before the cutoff (so document will be a little shorter than [words])
#' @return dupe_objects.json and data frame containing each id and all its duplicates. remove_ids.txt and character vector with list of ids to be removed. Files are in current working directory