minor optimizations of the modexp builtin

three small commits for HashDB and MemoryDB

use rust 1.18's retain to boost the purge performance

snap update

Allow IPFS server to accept POST requests

Dutch i18n from #5802 for master

Typos in token deploy dapp ui

A CLI flag to allow fast transaction signing when account is unlocked.

* Use randomized subscription ids for PubSub

* Use H64 instead of H128.

* iflet instead of match.

* Adding 0x.

darwin rustup default stable
snap - allow failure

Fixed mem write for empty slice

add --verify
add RUSTFLAGS="-C link-dead-code"

This reverts commit 6b874ced.

switch to RUST 1.18 and NodeJS 8.1

Fix JS tests