detour beam function and return closest

[ampreeT]

need more information on this (why hook this)
original description: detour CBeam::RandomTargetname -> compare for !player -> return closest

[Alienmario]

This should be done because !player will target the first player, resulting in beams potentially going through walls or even whole map, though not that common in the campaign.
To improve on this further, build a list of players with line of sight and choose at random.