change footer to include version
change 'download' btn to 'Open PDF Reader'
fixed audio player play and pause button issue on Android tablet
fixed the video points jump to 750 issue
prettify PDF container and related content container
makeing sidebar title vertically aligned
Merge branch 'develop' of https://github.com/learningequality/ka-lite into develop-beta-language
Adds 'get_leafed_topics' to return all topics in NodeCache that contain content.
Allow progress reports to flexibly accept playlists and topics to show progress.
Reinstates navbar option to show progress reports.
Merge pull request #2719 from rtibbles/user_progress

Re-enable User progress
Merge pull request #2698 from mrpau/feature/2472-have-makemessages-scan-handlebars-files-to-extract-translatable-strings

Modify `makemessages.py` to add the keyword for i18n for handlebars files.
Beta language packs checking
Merge pull request #2721 from 66eli77/develop-beta-language

Develop beta language
Merge branch 'develop' into feature/2472-have-makemessages-scan-handlebars-files-to-extract-translatable-strings