Add the #goo to allow use in C++.

Silence a few more warnings.
Strip down the mkfiles more.
Fix bug in X11 mouse handling, note groups.

include/cursor.h

@@ -1,3 +1,9 @@
+#ifndef _CURSOR_H_
+#define _CURSOR_H_ 1
+#if defined(__cplusplus)
+extern "C" { 
+#endif
+
 typedef struct Cursor Cursor;
 struct	Cursor
 {
@@ -5,3 +11,8 @@ struct	Cursor
 	uchar	clr[2*16];
 	uchar	set[2*16];
 };
+
+#if defined(__cplusplus)
+}
+#endif
+#endif