PANDA support

[lacraig2]

I forked this repo so I could make this neat project work with PANDA (a fork of QEMU that supports Record/Replay and plugins).

I expect this to get rejected because it's a huge change, adds a fair amount of extraneous code, and probably is not the direction you want to go.

That said I felt bad not "contributing back" so I figured I'd make an attempt at it and cleaned up a branch that was largely "mergeable".