GUI Tweaks

[cculianu]

• Add protocol version (e.g. '100') to the UI in a tiny corner in the View Pools.. window Addressed in b06307efa86f4abd4922951fcf7bc4482fd0c759 using a different approach.
• Add the "View pools..." (and perhaps CashShuffle settings?) to one of the drop-down menus in the UI
• See about strategies to "collapse" the Shuffle tx's in the history view (either a GUI toggle to hide them with or without some indicator they are there or some other mechanism such as a collapsable tree view thingamajig). See #83

[cculianu]

I decided against adding anything to the app menu for cashshuffle for now -- it's awkward to do from a plugin. May revisit this later. Closing.