Frags are displayed on keys popup during deathmatch

Subversion-branch: /branches/v2-branch
Subversion-revision: 2645
Hopefully complete implementation of player names and Strife player chat
features, which work differently than they did in DOOM.

If working properly, then this fully completes Chocolate Strife, aside
from any presently unknown issues.

Subversion-branch: /branches/v2-branch
Subversion-revision: 2646
Re-enable netgame check on code that enters chat state.

Subversion-branch: /branches/v2-branch
Subversion-revision: 2647