Planet deletion is working, but...

The user is able to delete **all** planets, which results in an unusable account.

There are two possible solutions:

* redesign account views to make them independent from planet objects
* redesign the planet deletion to prohibit the deletion of the *last* account

Additionally, the deletion confirmation needs more information (planet name, ...) and styling
Provide additional information in confirmation template
working on confirmation template
BUG: some imports missing
confirmation template ready
Quickie on issue https://github.com/Mischback/django-oweb/issues/17

Yeah, I know this branch is called issue15, but issue https://github.com/Mischback/django-oweb/issues/15 was fixed real quick and the solution applies to issue https://github.com/Mischback/django-oweb/issues/17 aswell.

So, here we are. Throw rocks if you never implemented two features in one branch. *narf*
Merge branch 'issue15' into development

Fixed https://github.com/Mischback/django-oweb/issues/15
Fixed https://github.com/Mischback/django-oweb/issues/17