Eliminate problematic js properties in non-debug builds:

js.gc_counter, js.gc_last_bytes, js.bytes, and js.max_bytes
Since these properties rely on internal JS context structure offsets, they're
not always compatible with replaced (upgraded or downgraded) JS library
(shared object or DLL) and can cause crashes in some cases. They can be
useful in some debugging cases, so I'm leaving them in the debug build, but
use with caution.

src/sbbs3/js_internal.c

@@ -38,7 +38,9 @@
 #include "sbbs.h"
 #include "js_request.h"
 
-#include <jscntxt.h>	/* Needed for Context-private data structure */
+#ifdef _DEBUG
+	#include <jscntxt.h>	/* Needed for Context-private data structure */
+#endif
 
 enum {
 	 PROP_VERSION