Updated a bunch of hyperlinks in documentation
Removed an erroneous leading slash introduced by a626bdf648a.
Fixed #21560 -- missing 'slug' field in example code
I updated the documentation, that the modelform now includes the 'slug' field.
Merge pull request #2058 from c-schmitt/fixes_21560

Fixed #21560 -- missing 'slug' field in example code
Fixed E124 pep8 warnings.
Moved imports to the top of the defaultfilters module.
Merge remote-tracking branch 'upstream/master'