added show_root_categories templatetag and tests
added template for new templatetag
Added docs for the new templatetag
Merge pull request #7 from mbrochh/templatetags

Templatetags
Version + changelog bump
Added unique=True to the categorie's slug field.
Fixed failing test / applied PEP8 on some files
Merge pull request #8 from mbrochh/failingtest

Fixed failing test / applied PEP8 on some files
Fixed typos
Added runtests.py for easier execution of tests without needing to setup a testproject.
Merge pull request #9 from mbrochh/runtests2

Added runtests.py for easier execution of tests without needing to setup
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Fixed templates mismatch
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Added a template tag to render all root categories with it's children (if present).
Modified docs as well.