`tasks` app models adapted to use the new `projects` generic model.
`tasks` URLs reviewed to use regex again.
Merge branch 'integration' of https://github.com/onepercentclub/bluebottle into integration
Fixes automatic slug generation in abstract `projects` model.
Merge branch 'integration' of https://github.com/onepercentclub/bluebottle into integration
Merge branch 'integration' into projects-generic
Fixed `projects` serializers to make use of the new generic model.
Fixed `projects.dashboard` to make use of the new generic model.
Merge pull request #128 from jose-lpa/integration

More `projects` generic model related fixes.