Changes up to rev. 3127, Feb 28

* Enable keyboard-navigation features: draw board elements using
  special background color when "focussed", and respond to arrow and
  space keys to move focus.

* implement "mini-window".  Now if you hold your finger for half a
  second on player's score or a bonus tile you'll see a mini-window
  giving more information.  If you are trading a mini-window will
  appear on the board.  You can also get these using focus and the
  center-nav key.  Given how fat our fingers are compared to the
  squares on the board I'm not sure how useful this is, at least if
  you're not using keyboard navigation.  Suggestions and opinions
  welcomed.

* implement Game->Final scores menuitem; remove Game->Game info
  menuitem.  (Game info and Configure bring up the same dialog
  conceptually, but in the former case it's read only.  I think the
  way this will work eventually is that you'll always "configure" the
  game even if all you want is information about it; and then if you
  do change something that can't be changed mid-game you'll get a
  confirmation alert like "This change requires that the game be reset
  (all moves and tile assignments discarded).  Do you want to do
  that?")

* Improve sizing and quality of fonts on the board.  I redid the
  calculation of how large a font I can use for both tiles and the
  board and think I've nailed it.  Please let me know if on your
  device it appears that letters could be any larger.  (Remember that
  if there's even one letter in the dictionary that extends below the
  baseline, e.g. J and Q for English using the standard Android font,
  then all other letters will have space below them.  The same applies
  if there are any accented letters.)

* Color bitmaps on demand so Catalan and Spanish "special" tiles' text
  is the same color as other tiles' text

* Improved Catalan translation (thanks Joan)

* Implement Game->Resend messages menuitem.  This only matters in a
  multi-device game.  I'm finding that Crosswords has trouble
  reconnecting when quit and restarted in the middle of a game.  This
  should help -- but I haven't spent any time debugging networking
  this week.

* Implement phonies handling.  Now if you choose Warn or Disallow when
  configuring a game and then play a word not in the dictionary the
  right thing will happen: you'll be asked to confirm if you've chosen
  Warn, and will lose your turn if you've chosen Disallow.

* Made temporary addition to Prefs dialog allowing to choose whether
  "anti-aliasing" and "sub-pixel rendering" are used when text is
  drawn on the board.

* fixed bugs 
- don't fail to redraw tray when dragged tile dropped to left of divider.
- default colors for players 3 and 4 were same as 1 and 2