Made AdBase.category optional. Resolves #27.
Implemented download of adclicks as csv through admin action. Resolves #30.
Updated django.conf.urls.defaults import.
Resolves #26.
Set up custom querysets on AdClick/AdImpression admins. Resolves #28.
Merge pull request #29 from melinath/ticket/27

Made AdBase.category optional. Resolves #27.
Merge pull request #31 from melinath/ticket/30

Implemented download of adclicks as csv through admin action. Resolves #...
Merge pull request #32 from melinath/ticket/26

Updated django.conf.urls.defaults import.
Merge pull request #33 from melinath/ticket/28

Set up custom querysets on AdClick/AdImpression admins. Resolves #28.