add missing header end comments

- ensures a consistent usage in header files
- also add a blank line after the copyright header where missing
- also remove orphan new-lines at the end of some files

src/version.h

@@ -1,6 +1,7 @@
 // Copyright (c) 2012 The Bitcoin developers
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
 #ifndef BITCOIN_VERSION_H
 #define BITCOIN_VERSION_H
 
@@ -52,4 +53,4 @@ static const int MEMPOOL_GD_VERSION = 60002;
 std::string FormatFullVersion();
 std::string FormatSubVersion(const std::string& name, int nClientVersion, const std::vector<std::string>& comments);
 
-#endif
+#endif // BITCOIN_VERSION_H