Add small hold effect when logging in, and separate post-cast timer for Phase.

Flashing on/off using Phase is becoming an issue and to fix this I've added a 1.5 sec (adjustable in-game) post-cast timer for Phase. This timer doesn't interact with other spell or swing timers, but prevents Phase from being cast again until the timer expires.

To prevent Phase becoming useless due to this, I've also added a 1.5 sec hold effect when logging on unsafe. Phase should still be the better option, but certain players won't be exploiting it to 'flash-walk' to safety.