ui papercuts

* added link to help dialog
* remove "Hide Main Window" -- much better UX, less buggy, and makes it possible raise window when it is obscured. To hide, just close window
* properly align login and logout buttons
* added non-functional decorative footer
* simplify wizard instructions
* clean up icons in mainwindow.qrc
* start to switch to SVG icons (is this compatible everywhere? if so, much better)
* better on/off/wait buttons: thinner border, smaller circles, smaller icon inside, nicer colors (for the white versions)