Use django.urls where appropriate

[rsalmaso]

Exctract from #755
Use django.urls if possible (django >= 1.11 compatible)

[codecov]

Codecov Report

Merging #795 into master will increase coverage by 0.03%.
The diff coverage is 94.11%.

@@            Coverage Diff             @@
##           master     #795      +/-   ##
==========================================
+ Coverage   69.85%   69.88%   +0.03%     
==========================================
  Files          99      100       +1     
  Lines        4339     4337       -2     
==========================================
  Hits         3031     3031              
+ Misses       1308     1306       -2

Impacted Files	Coverage Δ
src/wiki/plugins/links/wiki_plugin.py	0% <0%> (ø)	⬆️
src/wiki/forms.py	63.5% <100%> (ø)	⬆️
src/wiki/plugins/notifications/wiki_plugin.py	100% <100%> (ø)	⬆️
src/wiki/models/urlpath.py	81.66% <100%> (ø)	⬆️
src/wiki/plugins/attachments/urls.py	100% <100%> (ø)	⬆️
src/wiki/plugins/globalhistory/wiki_plugin.py	100% <100%> (ø)	⬆️
src/wiki/models/__init__.py	82.35% <100%> (+1.31%)	⬆️
src/wiki/plugins/notifications/models.py	67.34% <100%> (ø)	⬆️
src/wiki/models/article.py	83.25% <100%> (ø)	⬆️
src/wiki/urls.py	97.36% <100%> (ø)	⬆️
... and 12 more

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[benjaoming]

Maybe it's best to move this logic to wiki.core.compat ?

[rsalmaso]

Ops, use wiki.compat.
Should move?