Merge branch 'release/0.9.20'

accounts/account_manager.go

cmd/geth/admin.go

cmd/geth/info_test.json

cmd/geth/js.go

cmd/geth/js_test.go

cmd/geth/main.go

cmd/mist/gui.go

cmd/mist/html_container.go

cmd/mist/ui_lib.go

cmd/utils/flags.go

common/compiler/solidity.go

common/compiler/solidity_test.go

common/natspec/natspec_e2e_test.go

common/path.go

common/size.go

common/size_test.go

core/chain_manager_test.go

core/events.go

core/manager.go

core/transaction_pool.go