Spectator Mode having extra player slots

Servers should be able to have extra slots just for spectators.
This would allow you to still watch a game even while it is full, be able to spectate without off-balancing one of the teams -1 when a server is full, would make AFKing easier without messing up your team, would help admins be able to be on their servers while not effecting the game, and altogether improve how the spectator system works.

By default, as not to make the server work too hard, it could just be 1 extra slot for spectators before all other spectators effect the main "max players" number, but of course this could be changed by the server owner. This would mean if you have a max number of players of 20, and a max extra spectator slots of 5 you could have a total of 25 people playing/viewing the server. But if you have those 5 extra spectator slots and have 6 spectators your game could only have 19 players playing.

Many times I have felt like watching a match, or checking servers to see if I want to join or not, but often times servers are full and I can't. Even more often have I just wanted to spectate but felt like I would off-balance the game! So I feel this would be a helpful feature to have.
(Also you should be able to see all names, when spectating!)

 

I can already join full servers if I'm an admin on that server (Aphelion's CTF) but that might be because he assigned two extra slots for us. I'm not sure.