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
update travis to seperate different image library tests
fixed force_text import
add text filters

Add two filters: markdown_thumbnails, html_thumbnails. Those filters use
regex to replace images with thumbnails. The width of the thumbnails is
set to THUMBNAIL_FILTER_WIDTH which is by default 500.
Merge pull request #191 from relekang/filters

Add new text filters: markdown_thumbnails and html_thumbnails
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 pull request #188 from xyz666/fix_force_text

Fixed force_text import
Merge branch 'master' of github.com:mariocesar/sorl-thumbnail

* 'master' of github.com:mariocesar/sorl-thumbnail:
  fixed force_text import
Cleanup compatibility module
Merge pull request #193 from relekang/travis-config

Update travis to seperate different image library tests
Skip test