* crypto/bn256: full switchover to cloudflare's code
* crypto/bn256: only use cloudflare for optimized architectures
* crypto/bn256: upstream fallback for non-optimized code
* .travis, build: drop support for Go 1.8 (need type aliases)
* crypto/bn256/cloudflare: enable curve mul lattice optimization
* core/vm, crypto/bn256: switch over to cloudflare library
* crypto/bn256: unmarshal constraint + start pure go impl
* crypto/bn256: combo cloudflare and google lib
* travis: drop 386 test job
Péter Szilágyi
thomasmodeneis