New features and fixes: timelines, safari audio, practice course

CHANGE LOG - Features - Added timeline for user awards - Added 3 new awards: Create Classroom, Registered as teacher, created first classroom - Iconic KPIs in "navbar idea" to replace textual - Fixes - Practice course - changed algorithm to reduce frequency of seeing the same question in a session - News page is now in timeline format - Navigation area now shows percentage correct in past 24 hours, rather than all-time (which was a relatively meaningless statistic) - Improved mobile spacing on multiple components - Fixed Safari audio - it should now play on demand, and auto play depending on settings