Flag fixes and wep rendering

Fixed the flag not being dropped correctly on death, and started work to
fix/simplify rendering of weapons through colors. Now, we use
SetWeaponColor and SetPlayerColor to set colors, which only changes the
color of the model in places where it has been set to allow it. For eg,
shirts and pants on the players and the beam/glow effect on the phys
gun. Also added a global function to convert a Color table to a vector
color.