src: Updating code style to conform (more or less) to ndn-cxx style

Also, adding .clang-format that describes the applied style. Note that
this style requires a slightly customized version of clang-format.
diff --git a/utils/trie/counting-policy.hpp b/utils/trie/counting-policy.hpp
index 2c8656c..a44c290 100644
--- a/utils/trie/counting-policy.hpp
+++ b/utils/trie/counting-policy.hpp
@@ -32,76 +32,75 @@
  * @brief Traits for policy that just keeps track of number of elements
  * It's doing a rather expensive job, but just in case it needs to be extended later
  */
-struct counting_policy_traits
-{
+struct counting_policy_traits {
   /// @brief Name that can be used to identify the policy (for NS-3 object model and logging)
-  static std::string GetName () { return "Counting"; }
-
-  struct policy_hook_type : public boost::intrusive::list_member_hook<> {};
-
-  template<class Container>
-  struct container_hook
+  static std::string
+  GetName()
   {
-    // could be class/struct implementation
-    typedef boost::intrusive::member_hook< Container,
-                             policy_hook_type,
-                             &Container::policy_hook_ > type;
+    return "Counting";
+  }
+
+  struct policy_hook_type : public boost::intrusive::list_member_hook<> {
   };
 
-  template<class Base,
-           class Container,
-           class Hook>
-  struct policy 
-  {
-    typedef typename boost::intrusive::list< Container, Hook > policy_container;
-    
+  template<class Container>
+  struct container_hook {
+    // could be class/struct implementation
+    typedef boost::intrusive::member_hook<Container, policy_hook_type, &Container::policy_hook_>
+      type;
+  };
+
+  template<class Base, class Container, class Hook>
+  struct policy {
+    typedef typename boost::intrusive::list<Container, Hook> policy_container;
+
     // could be just typedef
-    class type : public policy_container
-    {
+    class type : public policy_container {
     public:
       typedef Container parent_trie;
 
-      type (Base &base)
-        : base_ (base)
+      type(Base& base)
+        : base_(base)
       {
       }
 
       inline void
-      update (typename parent_trie::iterator item)
+      update(typename parent_trie::iterator item)
       {
         // do nothing
       }
-  
+
       inline bool
-      insert (typename parent_trie::iterator item)
+      insert(typename parent_trie::iterator item)
       {
-        policy_container::push_back (*item);
+        policy_container::push_back(*item);
         return true;
       }
-  
+
       inline void
-      lookup (typename parent_trie::iterator item)
+      lookup(typename parent_trie::iterator item)
       {
         // do nothing
       }
-  
+
       inline void
-      erase (typename parent_trie::iterator item)
+      erase(typename parent_trie::iterator item)
       {
-        policy_container::erase (policy_container::s_iterator_to (*item));
+        policy_container::erase(policy_container::s_iterator_to(*item));
       }
 
       inline void
-      clear ()
+      clear()
       {
-        policy_container::clear ();
+        policy_container::clear();
       }
 
     private:
-      type () : base_(*((Base*)0)) { };
+      type()
+        : base_(*((Base*)0)){};
 
     private:
-      Base &base_;
+      Base& base_;
     };
   };
 };