Merge remote-tracking branch 'origin/master' into ser-wasmtime-api

# Conflicts:
#	Cargo.lock
#	client/executor/common/src/sandbox.rs
#	client/executor/wasmi/src/lib.rs
#	client/executor/wasmtime/src/function_executor.rs
#	client/executor/wasmtime/src/runtime.rs
#	client/executor/wasmtime/src/util.rs