Double Klondike download

v2.0
* Now allows selection of two card sizes.
* Fixed problem with digit separators in the Select Game dialog.
* Now uses standard C++ library Mersenne Twister 19937 generator (64 bit) for shuffles.
* All artwork now supports Retina displays with high-resolution images.
* Supports new toolbar/title bar arrangement.
* Supports new dark mode.
* Supports macOS 11.x.

v1.1
+ Adds animations for moves and autoplays to clarify card movement.
+ Displays the "open hand" cursor when a valid drop position is found during a move.
+ Supports fullscreen display.
+ Larger card layout for 1440x900 screens.