Fix typos.
Wrapper element for article title is no longer necessary.

Also, set flex properties on .controls to ensure their minimum width.
Show a hint about how to add feeds when the user doesn't have any.
Convert the first run page to flex layout.
Improve descriptions of the first run tutorial.
Fix regression: broken keyboard shortcut for collapsing/expanding items.
Tweak the feed settings dropdown to be more discoverable.
Adjust spacing of menupopups
Change wording of "Mark As Read" context menu actions.

"Mark {Feed, Folder} As Read" -> "Mark As Read"