fix: all: fixes to get emacs-chess working on 30.2

- added lexical-binding headers to all source files
- replaced make-variable-buffer-local with defvar-local throughout source code
- replaced deprecated cl library with cl-lib, including replacing assert with cl-assert to emacs-chess-steps.el
- added proper headers and footers to test files when missing
- populated chess images and chess sounds directory
- fixed defcustom calling directory-files without error handling.
  xboard installation no longer required.

2 files changed, 38 insertions, 0 deletions

diff --git a/pieces b/pieces
deleted file mode 160000
-Subproject e1fd1a04010df93f18ff1c1d8d62ea23ce96029
diff --git a/pieces/xboard/bdd29.xpm b/pieces/xboard/bdd29.xpm
new file mode 100644
index 0000000..99e5410
--- /dev/null
+++ b/pieces/xboard/bdd29.xpm
@@ -0,0 +1,38 @@
+/* XPM */
+static char *bdd29[] = {
+/* columns rows colors chars-per-pixel */
+"29 29 3 1",
+"  c black s dark_piece",
+". c green s dark_square",
+"X c white s light_piece",
+/* pixels */
+".............................",
+".............................",
+".............   .............",
+"............     ............",
+"............     ............",
+".............   .............",
+"............     ............",
+"..........         ..........",
+".........           .........",
+"........      X      ........",
+".......       X       .......",
+".......     XXXXX     .......",
+".......       X       .......",
+".......       X       .......",
+"........             ........",
+"........             ........",
+".........  XXXXXXX  .........",
+".......... X     X ..........",
+".........           .........",
+"......... XXXXXXXXX .........",
+"........             ........",
+"..........         ..........",
+"............     ............",
+"...                       ...",
+"..                         ..",
+"...           .           ...",
+"...   .     .....     .   ...",
+".............................",
+"............................."
+};