README enhancements
Merge branch 'master' of github.com:mariocesar/sorl-thumbnail

* 'master' of github.com:mariocesar/sorl-thumbnail:
  remove usage of deprecated generic simple views from django
Merge branch 'master' of github.com:mariocesar/sorl-thumbnail

* 'master' of github.com:mariocesar/sorl-thumbnail:
  add text filters
  Log the exception if the AdminImageWidget cannot generate the thumbnail instead of silencing it.
Merge branch 'master' of github.com:mariocesar/sorl-thumbnail

* 'master' of github.com:mariocesar/sorl-thumbnail:
  fixed force_text import
Cleanup compatibility module