docs: Updating documentation and license boilerplates in all files

Change-Id: I321fb0d85aaddf9150ed496fe03ee0e4dc738761
diff --git a/INSTALL.md b/INSTALL.md
index 4702e3f..f563f56 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -1,5 +1,5 @@
 ndn-cxx: NDN C++ library with eXperimental eXtensions
-===========================================================================
+=====================================================
 
 Supported platforms
 -------------------