Use the documented 5 line prolog in every sample application. Tidy up sample prologs and header code.

samples/path-test.cpp

@@ -20,7 +20,6 @@
  */
 
 #include <exiv2/exiv2.hpp>
-
 #include <iostream>
 #include <fstream>
 #include <sstream>
@@ -32,6 +31,9 @@ int main(int argc, char* const argv[])
 {
     Exiv2::XmpParser::initialize();
     ::atexit(Exiv2::XmpParser::terminate);
+#ifdef EXIV2_ENABLE_BMFF
+    Exiv2::enableBMFF();
+#endif
 
     if (argc != 2) {
         std::cout << "Usage: " << argv[0] << " file\n";