normalize file headers across **/*.{h,c}

include/debug.h

@@ -1,11 +1,11 @@
 /*
- * vim:ts=8:expandtab
+ * vim:ts=4:sw=4:expandtab
  *
  * i3 - an improved dynamic tiling window manager
+ * © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
  *
- * (c) 2009 Michael Stapelberg and contributors
- *
- * See file LICENSE for license information.
+ * debug.c: Debugging functions, especially FormatEvent, which prints unhandled
+ *          events.  This code is from xcb-util.
  *
  */
 #ifndef _DEBUG_H