Legacy 1.5.1

The final 1.x release on master.
1.x will no longer be maintained except for critical security updates.

Note: a modern 2.x release or a clone of master should be favoured whenever possible.

Changelog:

• Allow redirect of private front page
• Remove calls to GH raw
• Disable PHP errors
• Deprecate cheery theme
• Use int to stop overflow in DB
• Fix misc. bugs