Upgraded to Xenforo v2.3 RC 5

[StrangeWill]

So we deployed the new Forum software version 2.3 Release Candidate 5, this technically is still in-development software, but we wanted two major features:

1. Dark theme (aww yiss, check your "variations" configuration under your user profile)
2. Web hooks (we want to tie the Slack channels into the forums providing announcements when new threads are created)

If any major issues arise, feel free to reply here and I'll report them to Xenforo

Thanks!