WIP: ECIES

Do not pull this in.

I'm updating the way network communication encryption and authentication works to remove security vulnerabilities. I'm putting this WIP PR here now so you guys can see what files I'm editing so you don't significantly change anything while I work on this.

The files I'm editing are:
* PrivateKey.js
* Wallet.js
* WalletFactory.js
* WebRTC.js
* package.json
* test/index.html
* test.PrivateKey.js
* test.TxProposal.js
* test.network.WebRTC.js
Maybe we should throw and error here, according the "fail earlier" idea.