face: When there are no more events to process, pausing transport instead of closing it

Change-Id: I12ad55c6ef3b6b3fce4a5b3c679eb0c6dc3cfa07
Refs: #1314
diff --git a/src/transport/unix-transport.hpp b/src/transport/unix-transport.hpp
index 4a89bc8..f8114f5 100644
--- a/src/transport/unix-transport.hpp
+++ b/src/transport/unix-transport.hpp
@@ -36,6 +36,12 @@
   close();
 
   virtual void
+  pause();
+
+  virtual void
+  resume();
+
+  virtual void
   send(const Block& wire);
 
   virtual void