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/restrictions.cc
--- src/restrictions.cc.orig
+++ src/restrictions.cc
@@ -8,9 +8,9 @@
 // PURPOSE.
 
 #include "base.hh"
+#include "restrictions.hh"
 #include "safe_map.hh"
 #include "vector.hh"
-#include "restrictions.hh"
 #include "file_io.hh"
 #include "roster.hh"
 #include "database.hh" // for parent_roster