mint-arena: If scout, don't pickup haste

Haste powerup doesn't effect speed if scout class, so don't pick it up.

Back ported from Turtle Arena.
mint-arena: Change finished connecting and team change messages

Make team change message appear in console instead of center print.
Replaced 'so-and-so entered the game' message with team change message.
    Sometimes both were shown in team gametypes.
    Now team change is consistantly printed after spawn instead of entered game.
Don't show death message when switching to spectator. A team change message is shown instead.
Don't broadcast team change before spawn. It was getting printed before hand when teampref or g_autoteam set team.

Back ported from Turtle Arena, with some editional improvements.
mint-arena: Print all server-sent center prints in console too

Convert to a single line.
Skip the notify area though.
mint-arena: Make flag capture a center print

Back ported from Turtle Arena.
mint-arena: Show center print for destroying obelisk

Back ported from Turtle Arena.
Fix cg.skulltrails out of bounds access in Team Arena Harvester mode

In Team Arena's Harvester mode, players corrupt your memory from beyond
the grave. Gib the players to stop the corruption!

CG_PlayerTokens is called for player entities, including corpses.
The entity number is used for the index in cg.skulltrails which only has
MAX_CLIENTS elements. This results in incorrect memory being overwritten
for corpse entities (as the entity number is >= MAX_CLIENTS).

So limit skull trails to valid entities (entity number < MAX_CLIENTS).
mint-arena: Be more strict with cg.cur_*, clear when done in loops

Also fix a bad usage of cg.cur_ps.
mint-arena: Don't draw third person crosshair in first person dead view
mint-arena: If third person, only draw your award/team sprite in mirrors

Stops sprites from blocking view in third person.

Back ported from Turtle Arena.
mint-arena: Don't draw trailing CTF flag in third person

Trailing CTF flag blocks view in third person so only draw in mirrors.

Based on Turtle Arena, which doesn't draw it all all in third person.