Replaced .h C headers with c-prefixed version and added std:: prefix to C standard library usage (#90)

This was not done to stdint.h for brevity in type names. Also removed "using namespace std;".

wpilibc/shared/include/Base.h

@@ -79,7 +79,8 @@ struct HasBeenMoved {
 
 // Define make_unique for C++11-only compilers
 #if __cplusplus == 201103L
-#include <cstddef>
+#include <stddef.h>
+
 #include <memory>
 #include <type_traits>
 #include <utility>

wpilibc/shared/include/SensorBase.h

@@ -7,7 +7,8 @@
 
 #pragma once
 
-#include <stdio.h>
+#include <stdint.h>
+
 #include "Base.h"
 #include "ErrorBase.h"