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/rpcclient.h

@@ -4,7 +4,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef _BITCOINRPC_CLIENT_H_
-#define _BITCOINRPC_CLIENT_H_ 1
+#define _BITCOINRPC_CLIENT_H_
 
 #include "json/json_spirit_reader_template.h"
 #include "json/json_spirit_utils.h"
@@ -12,4 +12,4 @@
 
 json_spirit::Array RPCConvertValues(const std::string &strMethod, const std::vector<std::string> &strParams);
 
-#endif
+#endif // _BITCOINRPC_CLIENT_H_