* Tentative Web UI for the Printer device.
* timeout must be a positive value
* Change the attach device class method to accept a dict with arbitrary key value pairs of parameters to be passed to the protobuf interface, rather than hard coded ones. Also renames the RaCtlCmds.attach_image() class method to attach_device().
* Make download_to_iso() use the new attach interface.
* Dynamically get the form items for support devices.
* Change the data structure returned by RaCtlCmds.get_device_types() to a dict, which contains the supported parameters and their default values. Leverage this data in the web ui to derive the form fields from the capabilities of rascsi.
* Tweak UI labels.
* Update FileCmds.read_config() to work with the new RaCtlCmds.attach_device() method.
* Check for numeric value.
* Streamline the UI for support devices.
* Handle support devices better by the oled screen.
* Clean up html.
* Dynamically adjust form field size based on data length.
* Use the comparison operator that Python3 likes.
* Add SUPPORT_DEVICE_TYPES category, and add Host Service to it.
* Add webapp UI for attaching a support device.
* Make the OLED screen aware of the support device type.
* Tweak test to make it clear that this is experimental functionality.
* Tweak device type names
* Improve the device type selection UI
* Extend the image_files data structure with human readable device name, instead of having complex for loops in the jinja2 template.
* Leverage device type constants in the OLED monitor script
* Fix typo
* Generate the list of valid network devices that can be attached programmatically
* Fix typo
