Patch [2641] - Comms bug fix, HUD alerts last longer, and mission tweak

- Fixed (I hope) a long-standing uncommon bug, where exiting out of a mission with a communication playing, would not correctly clear the black backing or unpause the game enough.
- HUD Alerts (top right) now persist for double the time.
- Delayed the initial attack wave on Kreydell mission 2003 by 20s, was unreasonably harsh on slower players. Partial oversight from earlier version of the mission where you got control of the outposts automatically.
- Achievements menu should now more reliably adapt to resolution.