'remove' option not fully removed

[TheVastyDeep]

In PR 75 the remove option was removed, since the same functionality is available through the common option remove_field. However, the call 'remove(event) if @remove' was left in the code, and, much more importantly, the documentation still lists remove as being done after strip and before split. It is not, it is done after all of the mutate functionality as part of decorating the event.