Added patch from AC

- add missing includes "unistd.h" for compiling with gcc 4.7.0.

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@5096 b45a01b8-16f6-495d-af2f-9b41ad6348cc

libretroshare/src/pqi/authgpg.cc

@@ -34,6 +34,7 @@
 
 #include <util/rsdir.h>
 #include <util/pgpkey.h>
+#include <unistd.h>		/* for (u)sleep() */
 #include <iostream>
 #include <sstream>
 #include <algorithm>

libretroshare/src/pqi/p3dhtmgr.cc

@@ -23,6 +23,7 @@
  *
  */
 
+#include <unistd.h>
 #include <sstream>
 #include <iomanip>
 #include <stdio.h>

libretroshare/src/pqi/pqinetwork.cc

@@ -32,6 +32,7 @@
 #include <errno.h>
 #include <iostream>
 #include <stdio.h>
+#include <unistd.h>
 
 #include "util/rsdebug.h"
 #include <sstream>

libretroshare/src/pqi/pqissllistener.cc

@@ -39,6 +39,7 @@
 
 #include "util/rsdebug.h"
 #include <sstream>
+#include <unistd.h>
 
 const int pqissllistenzone = 49787;