Detect C++ language from all C++ file extensions

Author: alanhamlett

tests/samples/codefiles/c_and_cxx/cpp.h

@@ -0,0 +1,8 @@
+#include <stdio.h>
+#include <openssl/rand.h>
+
+main()
+{
+    printf("Hello World\n");
+    return 0;
+}