Add sights app, with first version of models and admin classes.
Make sights app a Django CMS App
Add sight.report app and first version of sight report form
Add sight's app initial data: jellyfishes
Name report sights URL and use it for link to report sights page.
Add form_valid method to SightReportView, adding reporter_id and saving sight
Add image fields to sight report form and correct enctype to form HTML tag
Make header_image an inheritable placeholder in base.html template
Merge branch 'sights_app'