Introduce a start for Burrow EVM as Sawtooth Transaction Processor

[benjaminbollen]

1. Introduces a copy of the "minimal" packages for the Ethereum VM to be connected as a TP:
   • burrow/common/math/integral
   • burrow/common/sanity
   • burrow/evm/abi
   • burrow/evm/opcodes
   • burrow/evm/sha3
   • burrow/evm
   • burrow/permission/types
   • burrow/version
   • burrow/word256
2. comments out the event system (and as a consequence the tests that rely here on the events)
3. all import paths are set to "sawtooth_burrow_evm/..."; but this likely does not work as the gopath is set to /home/ubuntu/go:/project/sawtooth-core/sdk/go
4. a second commit copies into sawtooth_burrow_evm/vendor three (optional) dependencies for reference:
   • github.com/stretchr/testify used in disabled test files
   • golang.org/x/crypto/ripemd160 for native contract at 0x00..03 ripemd160Func
   • gopkg.in/fatih/set.v0 for analysing jump destinations

[benjaminbollen]

Open considertions on my part:

1. how to deal with GOPATH, and dependencies (aim for none / vendored-in / package-management ) ?
2. I put these packages under directory burrow with the intent to be able to unfork at later stage more easily; I intend to make these packages top-level packages in burrow - where they are not already, ie evm
3. at it's most basic we now need to make an implementation for AppSate that translates the semantics of this interface to context operations in the handler;
   see https://github.com/benjaminbollen/sawtooth-core/blob/burrow-evm/families/burrow_evm/src/sawtooth_burrow_evm/burrow/evm/types.go#L46-L58

[jsmitchell]

Is there a good way to bring the vendor/ code in at build time instead of being in the repo?

[benjaminbollen]

I removed the commit with the vendor directory

[aludvik]

@jsmitchell We should consider using glide for go dependency management. Looks like @benjaminbollen's team is already using it and I think it will give us more control than the go get command we are currently using. I will research it a little more to verify we can make the swap.

[boydjohnson]

Tiny spelling error. Paniced -> Panicked. I don't think we need to change this before the PR goes in, but I was just noting it.

[boydjohnson]

I have some general questions/comments that I will make in the RocketChat #sawtooth-burrow room.

[benjaminbollen]

updated import path to reflect:

families/burrow_evm/src/burrow
families/burrow_evm/src/burrow/evm
families/burrow_evm/src/sawtooth_burrow_evm/handler