fix bug with redundant play/pause events and with displaying current mod

[AlecM33]

Resuming the timer failed to check if the ticking variable was a non-null reference before re-assigning. I believe this was leading to weird behavior where the user could fire off play/pause events with a certain timing that would eventually fail to stop an instance of ticking (because there are multiple in memory) and cause the "end timer" event to be fired, even though it appears to be paused. We can see that below - the timer is displayed as paused at 17.3 seconds. The last message we received from the server was a pause timer event. Yet then we receive the end timer event and are prompted with such.

Stopping the timer now nulls ticking and resuming the timer will check if ticking is null before restoring a reference.

We also fixed a bug where we were looking to display the current moderator when no such element existed in the DOM to populate with the data. This occurred right after a temp mod's powers were transferred away. Now we check if the client is a temp mod when processing the "kill player" event and, if so, do not attempt to update the content of that element (it will get updated when the client's view is synced as a part of the mod transfer event).