Add namespace around all files

src/extractor/external_memory_node.cpp

@@ -3,6 +3,11 @@
 
 #include <limits>
 
+namespace osrm
+{
+namespace extractor
+{
+
 ExternalMemoryNode::ExternalMemoryNode(
     int lat, int lon, OSMNodeID node_id, bool barrier, bool traffic_lights)
     : QueryNode(lat, lon, node_id), barrier(barrier), traffic_lights(traffic_lights)
@@ -37,3 +42,5 @@ ExternalMemoryNodeSTXXLCompare::value_type ExternalMemoryNodeSTXXLCompare::min_v
 {
     return ExternalMemoryNode::min_value();
 }
+}
+}