fixing the issue of the whiteboard annotations not being shown in the proper slide; cleaning the environment (events.xml, recorded flag) when the session was recorded but the record button wasn't used
Merge branch 'record-button' into mconf-live0.4.3
added a check on presentation publish script to avoid the duplication of thumbnails for a given slide
Merge branch 'record-button' into mconf-live0.4.3
included a statement that the exported recording is compatible with Mozilla Firefox only
Merge branch 'presentation-export' into mconf-live0.4.3

Conflicts:
	record-and-playback/presentation_export/playback/presentation_export/playback.html
fixing the issue with the promote/demote user feature in addition to the emoticons feature; when the moderator is demoted to viewer, the gear button was hidden, which avoids the user to set an emoticon