Make Evasion and UMD accessible as feats.

[Pandip]

Not sure how this would work specifically, but this might mitigate some of the soreness of pure classes struggling to stack up against multi-classes and dips.

The biggest source of woe for pure classes seems to be:

• lower saves
• lack of wand/scroll use
• evasion access
• tumble / AoO immunity

It feels like giving Evasion and UMD via feats to classes that wouldn't normally get access to them might help mitigate this.