mass update level form.
Merge branch 'development' of github.com:Coursemology/coursemology.org into development

* 'development' of github.com:Coursemology/coursemology.org: (40 commits)
  resolve conflict
  show mission files in submission gradings
  enrol count zero problem
  fix for annotation summary bug
  sidebar badge for No. of enrol requests
  paging preferences for most tables
  achievement locked icon preference
  fix for stats page crash when a user with achievement is deleted
  fixed exp awarding bug
  mission dependency and mission file submission option
  Sort by downcased names
  Actually sort by names
  fix initial exp_upadate_at value populate
  leader board ranking, same exp, first come first
  Sort student names in submissions
  added puma deploy script
  removed invalid annotations
  fix annotation error in comment summary page
  fix announcement bug that sending out notification when update announcement
  html edit for coding question description
  ...
add database.yml to gitignore.
remove compiled assests from development branch.