removed pytils from hard dependencies
removed sorl.thumbnail from hard dependencies
Merge remote-tracking branch 'origin/master' into remove_dependencies

Conflicts:
	docs/updates.rst
	pybb/models.py
	pybb/templates/pybb/avatar.html
	pybb/templates/pybb/post_template.html
	pybb/templates/pybb/user.html
More smarter load of thumbnail library

because django by default loads all custom libraries before page rendering, we have to use more smart loading of thumbnail library. Choosed template tags from https://bitbucket.org/jaap3/django-friendly-tag-loader to accomplish this task
removed django-pure-pagination from hard dependencies
install Pillow for tests
fixed get_profile function
another fix for get_profile
Merge pull request #72 from hovel/remove_dependencies

Remove dependencies