* master: (117 commits)
  More Model tests
  Better validation rules validity check
  Some tests for Model
  A bit more friendly behavior for unsetting a model attribute
  User WIP.
  Fixed Model::getFirstErrors()
  Finished AccessControl.
  Finished HttpCache.
  User WIP
  line ending fix.
  refactoring cache and db references.
  Fixed session bug.
  Finishes flash feature.
  refactored url creation shortcut method.
  HttpCache WIP.
  Finished AccessControl and HttpCache.
  Finished PageCache.
  finished fragment caching.
  fragment cache WIP
  bug fixes.
  ...