LDEV-1255: Moving the code for stopping jsps caching to a new custom tag, so that it can be applied consistently across all pages. Moved the utf-8 statements to the same tag so we don't have to remember to put them in all pages.
LDEV-1134: Changed strategy to suit how we now expect a sequence activity to look - a whole pile of subactivities joined with transitions rather than order ids.
LDEV-1248: Answers hidden in monitor were still showing in learner. Updated the export portfolio jsp so that it indicates hidden in the class view, and hides other students' answers that are marked as hidden in the learner view. In the same way, the two learner summary screens now only show a "hidden" response if it is the learner's own response.