Standard Perks Revision for EFU:M

[KillerB]

Several of the base perks are no longer 'relevant' for EFU:M. I am sure DMs are aware of this, this is just a polite bump.

In particular;

- Sewer Dweller (not sure what could be done here, maybe updated to Old Stones?)
- Slum Child (could definitely be updated to be relevant in Old Stones)