Ethsnarks

The major new feature in this snapshot is an in-circuit elliptic curve and matching Python and Solidity implementations, this allows signatures to be generated and verified across multiple implementations. However, this is still a work-in-progress.

In this snapshot the following changes have been introduced:

* Imported Baby JubJub in-snark curve code
* Solidity implementation of Baby JubJub curve
* EdDSA Python implementation
* Pedersen Hash Python implementation
* Python support for extended twisted Edwards, Edwards YZ and Montgomery XZ coordinates
* Reduce gas of LongsightL round function
* End-to-end tests for Miximus
* Fixed security bug in MiMC-p/p
* Fixed security big in Miximus

In this snapshot the following changes have been introduced:

* Faster build times, by compiling only a subset of `libff`
* DEBUG and `assert` enabled by default, catches programming errors
* Fixed bug with `bit_list_to_ints()`
* Builds on OSX working again
* Added `FQ` class for the in-snark scalar curve
* Updated the python Shamir's secret sharing scheme implementation (needs more work)
* Initial 'incremental merkle mountain range' implementation
* MiMC / LongsightL implementation
* Miyaguchi-Preneel OWF construct
* LongsightL + Miyaguchi-Preneel, field-native merkle tree
* Cleaned up Miximus + tests to use new merkle tree

Examples of prover built with NodeJS.