Manual flashcard marking, fixes, settings, chat, bookmarks, note

CHANGE LOG - FEATURES: - NEW: Ability to mark your own answers with flashcards. As an optional setting, you can now specify how well you knew the card, if you prefer to mark yourself rather than let the system decide. Note: Course owners can disable the marking of flashcard answers in their course settings if they prefer their students not to be able to do this. By default, it is allowed. - Added option to recalibrate days-next-due after turning the algorithm so words are not lost far in tnto the future - Added new tools: Bookmarks, notes, live chat 1) Notes: Save notes about any page, course, level or question whilst you learn 2) Chat: Chat with other users, in either the general channel, or course specific channels 3) Bookmarks: Add a bookmark to any place on the site, or save your external links for notes 4) All classrooms now have an optional private live chat - FIXES - Improved speech recognition for textual numbers, e.g. ochenta y uno would be heard as "81", it is now also recorded as "ochenta y uno" to match textual questions - Fixed issues in classrooms which would not let you edit certain privacy options - Improved rendering performance of flashcards - Fixed an issue where updating course settings would not update user settings accordingly for several minutes when applying certain restrictions - Reautofocus text box for typing after playing audio