Adding some logging
Converting (most) of the existing uses of error_log to idno logging
Merge branch 'logging' into logging2
s/idno/known
Migrating to new logging
Merge pull request #416 from mapkyca/logging2

Awesome logging code from @mapkyca. Thanks Marcus!
Replacing header function for nginx compatibility.

Thanks to Elliot Tucker!
Hubs should ideally not connect to themselves
A little cleanup.
Introducing 'antiplugins' and 'alwaysplugins' in config.ini
Sites now have closed registration by default
Email address is automatically filled in on first registration

Fixes #410
Updates to on boarding
Cleaning up logging code
Default value for known_hub
Allow Known to send messages (e.g. upgrades) to admin screen
Display retrieved upgrade messages
Retrieve messages on publish screen
Minor code cleanup
Improved color balance on Cherwell theme

Fixes #418