initial ui spec added. ready for team review?

PP01: "Users may be able to infer a domain's profile from the actions that are
available on various nodes in the Runtime Explorer."  - I think, this should be
more specific. At least say that the actions are available over on nodes, which
belong to the registered server. There would be better picture.

PP02: There is not clear which steps of the wizard the specification describes.
I think it's the second step.

PP03: The comboboxes for Domain and Profiles should have the same width.

PP04: There are mentioned three ways, how the UI should behave for "pre V2"
platform and "V2" platform. I think there is the fourth way. The profile
combobox will be always enabled, but for "pre V2" will contain only the Default
value. I think that it's common way, that the combobox shows only the supported
values. IMHO this is the right way how it should behave. Then you have to solve,
how to explain, why the combo box is disabled or enabled.

I have updated the spec to address pp02,pp03,pp04.

I am unsure how to address pp01, though.

committed