Compile DIAL client and server for macOS.

Changes:
* Added method to get mac and ip address for OSX. Current Linux method
of query via SIOCGIFCONF doesn't work. Added code to read via getifaddrs() API.
* Put non OSX specific code under #ifdef flags.
* Removed few linker libraries which are not required (lcares and lrt).
* Fixed many warnings.

Tested on: OSX 10.12

client/main.cpp

@@ -136,7 +136,7 @@ static void runConformance()
         else 
         {
             printf("DIAL server not found\n");
-            printf("%Zu available server(s): \n", list.size());
+            printf("%zu available server(s): \n", list.size());
             printServerList(list);
         }
     }