Correctly handle a recording start being the last event in a recording.

[HTML5] - logoutRouteHandler Fix

[HTML5 2.0] Presentation Manager 

In some unusual cases, the recording start can be the last event in the
events file, or at least have the same timestamp as such.

Add some code to check the array bounds and break if needed, so we
don't check the timestamp on the (non-existant) event after the last
event.

[HTML5 2.0] Refactor UserList Components

Merge 2x-mconf branch into master

Revert "[HTML5 2.0] Presentation Manager"

Don't crash playback if text is not available for a slide.

This happens when the slide is a plain image, for example.
Fixes #4425

 - manage a pool of libre office instances so we can process multiple…

[Flash Client 2.0] Add log for invalid or failed presentation conversion