doc/routeserver: Remove needless figures, centre and tweak other figs

* routeserver.texi: The full-mesh v RS topology diagrammes are fairly obvious
  and don't deserve so much space.  As smaller wrap-floats they might be
  acceptable, but there seems no way to access that TeX feature from
  Texinfo.  So nuke them.

  Centre the 2 other figures. Tweak size to avoid bbox overflow messages.
diff --git a/doc/routeserver.texi b/doc/routeserver.texi
index f4a4546..5fb8cba 100644
--- a/doc/routeserver.texi
+++ b/doc/routeserver.texi
@@ -60,20 +60,10 @@
 @end itemize
 
 @float Figure,fig:normal-processing
-@image{fig-normal-processing,400pt,,Normal announcement processing}
+@center @image{fig-normal-processing,400pt,,Normal announcement processing}
 @caption{Announcement processing inside a ``normal'' BGP speaker}
 @end float
 
-@float Figure,fig:full-mesh
-@image{fig_topologies_full,120pt,,Full Mesh BGP Topology}
-@caption{Full Mesh}
-@end float
-
-@float Figure,fig:route-server
-@image{fig_topologies_rs,120pt,,Route Server BGP Topology}
-@caption{Route Server and clients} 
-@end float
-
 Of course we want that the routing tables obtained in each of the routers
 are the same when using the route server than when not. But as a consequence
 of having a single BGP peering (against the route server), the BGP speakers
@@ -173,7 +163,7 @@
 @end itemize
 
 @float Figure,fig:rs-processing
-@image{fig-rs-processing,450pt,,Route Server Processing Model}
+@center @image{fig-rs-processing,430pt,,Route Server Processing Model}
 @caption{Announcement processing model implemented by the Route Server}
 @end float