Rework netcat-alike to be a proper mode, with -B argument.

--HG--
branch : dbclient-netcat-alike
extra : convert_revision : b02ba6628cf2095017c60d202ac630f231e6b553

chansession.h

@@ -78,6 +78,9 @@ void addnewvar(const char* param, const char* var);
 void cli_send_chansess_request();
 void cli_tty_cleanup();
 void cli_chansess_winchange();
+#ifdef ENABLE_CLI_NETCAT
+void cli_send_netcat_request();
+#endif
 
 void svr_chansessinitialise();
 extern const struct ChanType svrchansess;