all: Adding typedefs near forward declarations of Interest/ContentObject/Name

refs #29
diff --git a/model/fib/ndn-fib.h b/model/fib/ndn-fib.h
index 85e0eaf..6e21214 100644
--- a/model/fib/ndn-fib.h
+++ b/model/fib/ndn-fib.h
@@ -30,6 +30,7 @@
 namespace ndn {
 
 class Interest;
+typedef Interest InterestHeader;
 
 /**
  * \ingroup ndn