JILS-49: PHP7 Support

There's not been any development activity on JILS in quite some time, so the codebase is very outdated.

My instance of it has been quietly sat on a CentOS 6 (i.e. PHP 5.3.3 with backported security patches) box that I'm now trying to migrate away to, so as a result have needed to port JILS over to working on PHP7

So far, that's largely been hacked together in place (will attach patches), but it's almost certainly worth the effort of bringing the codebase up to date for easier deployment onto more modern platforms.