Added id strings to the tops of buttons_*.c files which were missing their

correct format. CVS expands $Id$ to the format you usally see at the tops
of files and these only had $Id: which CVS ignores.

source/blender/src/buttons_logic.c

@@ -1,5 +1,5 @@
 /**
- * $Id: 
+ * $Id$ 
  *
  * ***** BEGIN GPL/BL DUAL LICENSE BLOCK *****
  *