config.php: remove unused constants
config.php: remove unused constants

* `IRC_BOT_SOCKET` is unused
* `GENERATOR`, `HANGAR`, etc. are unused in favor of `PLANET_*`
* Moved a couple constants to more natural categories

hemberger/smr,hemberger/smr,smrealms/smr,smrealms/smr,hemberger/smr,hemberger/smr,smrealms/smr