NeuInk 0.4.3

Two Home and Library fixes, plus a larger Library cover grid.

• Home: on the app grid, a swipe that starts at the left edge of the screen (a page swipe) no longer opens the
  most recent book. Only the physical Back button does.
• Library, Recently Opened: books that were never opened now show their cover. It is built once, when its page is
  first shown, and kept in the book's cache folder; books without a cover image are marked so they are not retried.
• Library, Grid Size: a new Library setting switches the cover grid between 3 x 3 and 2 x 2 (larger covers).
• Library menu, Generate All Covers: builds the covers of every book at the current grid size, in any view or sort,
  with a progress popup and a Cancel button (Back). Covers already built are skipped.
• Translations for the two new strings in all languages.