Check for empty content since COM_Parse() never returns NULL.

Ref. git://github.com/darklegion/tremulous.git 799dfd2151d8b8a732d28b90627ba377ced38a60
Do not bail out of parsing particle script files when a duplicate name is seen.

Ref. git://github.com/darklegion/tremulous.git 799dfd2151d8b8a732d28b90627ba377ced38a60
Add information about IP address masks to the adjustban help text.
Calculate some exponentiation more efficiently/sensibly in bg_lib.c
Show who built a destroyed structure in buildlog
use current player origin in G_RoomForClassChange()

https://bugzilla.icculus.org/show_bug.cgi?id=5004
use the specified trace height correctly in G_WideTrace() (r4sh)

https://bugzilla.icculus.org/show_bug.cgi?id=5231
Revert didn't restore marked status
Periodically update scoreboard when visible.

This will also update pings during intermission.
Smarter way to check if teamoverlay info should be sent.
Don't send upgrade field for aliens.
Fix /builder's buildlog entry no. display.

(Fix ported from https://github.com/darklegion/tremulous)
Refactor some of CG_ParseParticle.
Fix some non sequiturs.
Merge branch 'master' into from-trem
Replace some comparisons with empty strings with equivalent fast tests.
De-duplicate cgame colour parsing code.