Updated Spawn (NPC, Vehicle, SENT) Permissions

Normalized spawn permissions to work similarly to "GM.Config.adminweapons".
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Merge branch 'patch-4' of github.com:johndoeno001/DarkRP
Amended #1365

Abstracted the admin check. It was the same in every spawn function. Code duplication is bad.
Fixed error when no one could spawn the thing (the phrase unable requires two arguments)
Changed config to reflect the changes. No one would know about it otherwise.
Changed the default settings to make no one able to spawn vehicles or NPCs.
    This is in accordance with the ideal that admins should be equal to other players.