Better model/attribute names

[mikek]

I am sorry to bring this up again, but if the app is going to be an example, this is something to consider.
Since namespace is not the only thing that NewsBlogConfig model can store... what is the better name for a namespace FK? app_config or app_hook_config or just config? @yakky what is your preference? Doing it early will be less painful.

I've also tried renaming Article to Entry (as a more general name for bog post and news article). Both Django and South migrations are straightforward, renaming templates and all context variables was also possible. The thing that have eventually stopped me was a huge number of article mentions in the test suite =) This would also affect any project already using the app a lot. Article is not a that bad name after all, so renaming a model seems not to be worth it.

[yakky]

probably app_config is the most sensible as it's kind of self explanatory

[mikek]

Implemented in #68