Restructure so messages and code specific to NETLINK_ROUTE are in one file

examples/route_lo.rb

@@ -0,0 +1,16 @@
+LIBDIR = File.expand_path(File.join(File.dirname(__FILE__), '..', 'lib'))
+$LOAD_PATH.unshift LIBDIR
+
+require 'pp'
+require 'netlink/route'
+
+# Example of use of low-level API for NETLINK_ROUTE socket.
+# Each of these method calls performs a netlink protocol exchange.
+
+nl = Netlink::RTSocket.new
+puts "*** links ***"
+pp nl.read_links
+puts "*** addrs ***"
+pp nl.read_addrs(:family => Socket::AF_INET)
+puts "*** routes ***"
+pp nl.read_routes(:family => Socket::AF_INET)