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, 46 insertions, 0 deletions

diff --git a/pieces b/pieces
deleted file mode 160000
-Subproject e1fd1a04010df93f18ff1c1d8d62ea23ce96029
diff --git a/pieces/xboard/nll37.xpm b/pieces/xboard/nll37.xpm
new file mode 100644
index 0000000..e850cb0
--- /dev/null
+++ b/pieces/xboard/nll37.xpm
@@ -0,0 +1,46 @@
+/* XPM */
+static char *nll37[] = {
+/* columns rows colors chars-per-pixel */
+"37 37 3 1",
+"  c black s dark_piece",
+". c gray s light_square",
+"X c white s light_piece",
+/* pixels */
+".....................................",
+".....................................",
+".....................................",
+".....................................",
+"......... ...... ....................",
+".........   ... X ...................",
+"......... XX . XX ...................",
+"......... XXX  XX    ................",
+"......... XX X XX XXX  ..............",
+"........ XX XXXXXXXXXXX  ............",
+"........ XXXXXXXXXXXXXXX  ...........",
+"....... XXX XXXXXXXXXXXXX  ..........",
+"....... XX  XXXXXXXXXXXXXX  .........",
+"....... X  XXXXXXXXXXXXXXXX .........",
+"...... XXXXXXXXXXXX XXXXXXX  ........",
+"...... XXXXXXXXXXXX XXXXXXXX ........",
+"...... XXXXXXXXXXXX XXXXXXXX  .......",
+"..... XXXXXXXXXXXXX XXXXXXXXX .......",
+"..... XXXXXXXXXXXX XXXXXXXXXX  ......",
+".... XXXXXXXXXXXX  XXXXXXXXXX  ......",
+"... XXXXXXXXXXX  . XXXXXXXXXXX ......",
+"...   XXXXXXX  ... XXXXXXXXXXX  .....",
+"...  XXXXXXX .... XXXXXXXXXXXX  .....",
+"... XXXXXXX ..... XXXXXXXXXXXX  .....",
+"... XXX XX ..... XXXXXXXXXXXXX  .....",
+"....    X ..... XXXXXXXXXXXXXXX .....",
+"........ ...... XXXXXXXXXXXXXXX  ....",
+".............. XXXXXXXXXXXXXXXX  ....",
+"............. XXXXXXXXXXXXXXXXX  ....",
+"............ XXXXXXXXXXXXXXXXXX  ....",
+"............ XXXXXXXXXXXXXXXXXX  ....",
+"........... XXXXXXXXXXXXXXXXXXX  ....",
+"........... XXXXXXXXXXXXXXXXXXX  ....",
+"...........                      ....",
+".....................................",
+".....................................",
+"....................................."
+};