*    Updated the phpDoc comments to match the code
*    Added return statements
*    Added return values

#655 allow core:php to manipulate all of the state

Sorry, I broke it last night!

http_response_code() was introduced in 5.4 and that's our minimum now

Closes https://github.com/simplesamlphp/simplesamlphp/issues/962

It was deprecated in Twig 1.x and removed in 2.0.

This setting had to be an absolute path before.. This change is backwards compatible (absolute paths still work)

Use declared names of methods and classes

Removed duplicate json properties

Replaced <tt> tags with <code> tags

Add logoff button for admin-interface

This means we can remove the crystal_project icons when removing
the old templates.

Closes: #952

There's some redundancy now since the code must support the old
and new template. The links variety is not very beautiful, but the
old one wasn't either..

Also search for "en" as a final fallback language to find a displayable
name should such a name not be found in the current language and the
default language.

When we remove old templates we can also remove silk.

The former is no longer online.

There's a link straight above to the docs, a link to the rest
of the website in the footer, this paragraph is highly redundant.
It links to rnd.feide.no which is down.

This is likely way more informative for the average person
clicking the link - and linking directly to github only
stimulates people asking help questions in issue tracker.