require_login() now has option for $role and check_nonce uses $_SESSION
Fixed typo (Exeption -> Exception) and several methods for sanitizing data.

See method documentation.
Fixed typo (Exeption -> Exception) and added several methods for sanitizing data.

See method documentation
session class now stores cookie paramaters and  can be destroyed.

Also, avoid duplicate code in if/else during __construct by moving to the end
of conditional statements instead of repeating inside.
Merge commit 'b3607fdd1b51ed812560c2c0779417978e2e1658' into dev
Destroy session on logout and create new. Notifications on log in/out
Better handling of REDIRECT_URL (in case not based from DOCUMENT_ROOT).

Now correctly getting URL whether or not located in DOCUMENT_ROOT
Add favicon after body > header h1
Add `url` to creating posts and trim() everything
pointer-events: none when offline.

I really don't like that this is done in CSS, but it works.
When getting links to posts, exclude main (`url` = '')