Feature #21 - Consent form and DateTimeField to HowSolved

[Elthan]

Closes #21

• Consent form page with the options to consent, delete the user, or sign out
• Middleware that will redirect any user that has not consented to the form to the consent form
• Options to disable consent middleware redirect
• Option to customise consent form
• Migrations for howsolved datetime and consent datetime
• Option to add custom template
• Link to consent form from profile page and consent datetime
• trix_settings.py which was accidentally added
• trix-no-print to pager
• Documents describing how to use custom consent form

[torgeirl]

@Elthan: seems there's something missing with the Approve button. It currently does nothing, at least on the test server.

Also, does the delete button depended on it's URL (mine says /user/delete/1, which also is my user ID)?