hooks: drop 'server_url' parameter The parameter might be conceptually nice, but it was only available for 2 hooks. To be really useful, it should have been available everywhere. It also only reported the URL from the web request that initiated the hook ... and as such it does some layering violations. The user URL might be the address that should be used internally from the hook. And it can conceptually not be made available actions that doesn't originate from a user web request. It seems much better that custom hooks configure what they want to do. Perhaps by reading the .ini file and using canonical_url.