LocalBooks: Update 'wide' by hand

It turns out that the onWidthChanged handler was running before the wide
property was updated.  When you drag a window wider, this is triggered
often enough that you don't notice the problem.  But when you rotate a
device, it only happens once, so you get the wrong layout.
Add translator comments for short strings
Lock portrait orientation while reading book

We want to lock the current orientation, but support for that is wanting
(#38).  Rotating while reading often confused Monocle (#32), so we
should disable that, and the bottom edge is broken when the screen is
rotated.  So let's keep it in portrait mode for now.