[Feature] Blind trait

[CandleCandleCandles]

Pretty simple stuff. As an analogue for Deaf trait, why not a Blind trait? Could make for even more of a challenge, especially because of being unable to use special glasses.

https://github.com/goonstation/goonstation-2016/pull/63

[kyle2143]

Yes, this should exist. But you should probably check to make it so you can't also take near sighted or cat eyes traits. Also remove that single line last change that does nothing.

[Spoodle]

Pretty cool. I don't see a reason not to add it.