A function macro named E clashes with internal boost definitions.  Rearrange
the order of header inclusion so that affected boost headers are included
before monotone defines the macro.

Also, stop bundling boost/circular_buffer, which is available in current
versions of boost. From Fedora.

Index: src/rcs_file.hh
--- src/rcs_file.hh.orig
+++ src/rcs_file.hh
@@ -10,9 +10,9 @@
 #ifndef __RCS_FILE_HH__
 #define __RCS_FILE_HH__
 
-#include "vector.hh"
 #include <map>
 #include <boost/shared_ptr.hpp>
+#include "vector.hh"
 
 struct rcs_admin
 {