correct staticfiles imports

the `staticfiles` module is inside `django.contrib`
Merge pull request #365 from hzy/patch-1

Correct staticfiles imports
Stupid IE7. Close #337.
bump version
Fix tests
Add `*.styl` to built-in finders' ignore patterns
Merge pull request #383 from emyller/master

Add `*.styl` to built-in finders' ignore patterns
Improve middleware tests
Fix url rewriting. Close #388
Fix formatting.
bump version
rename template tags to be more obvious
experiment with a collector process

The idea is to have a process similar to collecstatic, and
copy files in a temporary directory.

This avoid storage that use finders, streamline dev process with
production process, and make compilers easier to deal with.
update documentation
reintroduce python2.6 support
test against django 1.7c1
start documenting changes
style check
fix django 1.7 tests warning
test against Django 1.7