cmd/*: add license headers

cmd/ethereum/cmd.go

cmd/ethereum/flags.go

cmd/ethereum/main.go

cmd/ethereum/repl/console_colors_windows.go

cmd/ethereum/repl/repl.go

cmd/ethereum/repl/repl_darwin.go

cmd/ethereum/repl/repl_windows.go

cmd/mist/assets/ext/big.js

cmd/mist/assets/ext/ethereum.js

cmd/mist/assets/ext/filter.js

cmd/mist/assets/ext/html_messaging.js

cmd/mist/assets/ext/http.js

cmd/mist/assets/ext/qml_messaging.js

cmd/mist/assets/ext/qt_messaging_adapter.js

cmd/mist/assets/ext/string.js

cmd/mist/assets/muted/muted.js

cmd/mist/bindings.go

cmd/mist/debugger.go

cmd/mist/errors.go

cmd/mist/ext_app.go