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/model/cs/content-store-nocache.hpp b/model/cs/content-store-nocache.hpp
index ac7ced7..5745821 100644
--- a/model/cs/content-store-nocache.hpp
+++ b/model/cs/content-store-nocache.hpp
@@ -20,7 +20,7 @@
  */
 
 #ifndef NDN_CONTENT_STORE_NOCACHE_H
-#define	NDN_CONTENT_STORE_NOCACHE_H
+#define NDN_CONTENT_STORE_NOCACHE_H
 
 #include "ns3/ndnSIM/model/cs/ndn-content-store.hpp"
 
@@ -32,49 +32,45 @@
  * @ingroup ndn-cs
  * @brief Implementation of ContentStore that completely disables caching
  */
-class Nocache : public ContentStore
-{
+class Nocache : public ContentStore {
 public:
   /**
    * \brief Interface ID
    *
    * \return interface ID
    */
-  static
-  TypeId GetTypeId ();
+  static TypeId
+  GetTypeId();
 
   /**
    * @brief Default constructor
    */
-  Nocache ();
-  
+  Nocache();
+
   /**
    * @brief Virtual destructor
    */
-  virtual
-  ~Nocache ();
+  virtual ~Nocache();
 
   virtual Ptr<Data>
-  Lookup (Ptr<const Interest> interest);
+  Lookup(Ptr<const Interest> interest);
 
   virtual bool
-  Add (Ptr<const Data> data);
+  Add(Ptr<const Data> data);
 
   virtual void
-  Print (std::ostream &os) const;
+  Print(std::ostream& os) const;
 
   virtual uint32_t
-  GetSize () const;
+  GetSize() const;
 
   virtual Ptr<cs::Entry>
-  Begin ();
+  Begin();
 
   virtual Ptr<cs::Entry>
-  End ();
+  End();
 
-  virtual Ptr<cs::Entry>
-  Next (Ptr<cs::Entry>);
-
+  virtual Ptr<cs::Entry> Next(Ptr<cs::Entry>);
 };
 
 } // namespace cs