Merge branch 'master' into chore/fix-tempdir-dependency

* master:
  Refactor evm Instruction to be a c-like enum (#8914)
  Fix deadlock in blockchain. (#8977)
  snap: downgrade rust to revision 1.26.2, ref snapcraft/+bug/1778530 (#8984)
  Use local parity-dapps-glue instead of crate published at crates.io (#8983)
  parity: omit redundant last imported block number in light sync informant (#8962)
  Disable hardware-wallets on platforms that don't support `libusb` (#8464)
  Bump error-chain and quick_error versions (#8972)