Fix Leap support/Rework reflection

Leap support was broken after Leap removed Boost from the contract environment. I could add my own copy back in, but the Leap folks wrote this Bluegrass library which works almost as well and is way less bulky.

Along the way, I reviewed reflection, both mine and Leap's, and decided that Leap's has some good ideas that mine could benefit from, so I redesigned the BAL's reflection to take the best of Leap's design and my own, which led to dropping support for Peerplays as they no longer want to support Graphene and thus I can no longer support them with updates.

At this point, reflection is now working again on the new design and everything should be working on Leap.