Recording events archiver: fix syntax errors

I had renamed prev_event to previous_event, but missed a couple of spots.

Playback loading closed captions

Sort events when writing the events.xml file

BigBlueButton can sometimes write events out of order - this particularly
seems to affect the final RecordStatusEvent in a meeting which was ended
while recording was still running. This breaks the recording processing
scripts.

As a workaround, sort the events as they're being written into the events.xml
file. We have the following properties:

* The input data is already mostly sorted
* Items in the wrong position will be no more than a couple spots off from where
  they should be
* We should not change the relative order of events with the same timestamp.

The best algorithm to use here is a simple insertion sort. When adding each new
event to the XML structure, it scans backwards through existing events until it
finds the correct position.

For #6035

Make feedback work on logout

Fix incorrect reference in pres isDownloadable

Handle setting presentation as downloadable prior to uploading it

Center user avatar icons in Edge

Make the help link configurable

Add texts extracted from slides for accessibility

Pulled the latest html5 client locales; added cs_CZ

Presentation download

Replace double quotes in audio name with single quotes - 2.2 edition

Useful HTML5 sip.js bridge errors

Add defaults for Chrome screenshare link and key to config.xml template

Update share youtube video label

Recording: Fix handling of links in chat messages