release 1.11

• Deep linking
  • open course description by url in app (with empty states)
  • open syllabus by url in app (with empty states)
• Suggestion for sign in or sign up if user open by url and not signed
• improve instructor list in detailed info
• upgrade GCM --> FCM
• improve course detail screen --> Material design oriented
• fix ambigious progress
• SQL challenge icon was updated
• Header improve for courses, sections, units, videos
• Comments
  • delete comments
  • zero comments state from step list
  • show deleted comments for staff
  • fix bug when "\n" was not working in html
  • fix bug: show more without internet connection
  • fix bug: send reply, page > 2, show more
  • show text of comment for deleted (stuff)
• LaTeX improvements
• Join in section if user is not enrolled