No need to put this in try/catch

NotFoundExceptions will be catched by the page system which will
generate a proper 404 page.
Fix date parsing code in article editor

Now properly allows to delete an event date.
Add CSRF protection to article edit page

Article edits/deletions cannot be forged anymore, even when recklessy
clicking on malicious links.
Remove obsolete method

This method doesn't even function properly anymore. It also wasn't used
anymore.
Parse legacy null dates in the database

Before the database refactor the date "0000-00-00 00:00:00" was saved to
the database when saving a null date. The date reading code has been
updated to account for this.