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/netcmd.cc
--- src/netcmd.cc.orig
+++ src/netcmd.cc
@@ -8,11 +8,11 @@
 // PURPOSE.
 
 #include "base.hh"
-#include "vector.hh"
 #include <utility>
 
 #include "constants.hh"
 #include "netcmd.hh"
+#include "vector.hh"
 #include "netio.hh"
 #include "numeric_vocab.hh"
 #include "sanity.hh"