Expand Simphony-Remote start command in rest API to include startupdata

[flongford]

The remoteapprest app start command should accept a --startupdata option, specifying the path to a file that would be used at startup, using the framework provided in #560.
This probably involves editing the tornado-webapi module as well, since it would parse this option and send it back to Simphony-Remote to start the container.