Add DirectoryIterator & DirectoryIterator::operator = (const DirectoryIterator &)

Because every class with pointer members should have one.

src/platform/StdFile.cpp

@@ -849,6 +849,14 @@ DirectoryIterator::DirectoryIterator(const DirectoryIterator &other)
 {
 	++p->ref;
 }
+
+DirectoryIterator & DirectoryIterator::operator = (const DirectoryIterator & other)
+{
+	p = other.p; iter = other.iter;
+	++p->ref;
+	return *this;
+}
+
 DirectoryIterator::~DirectoryIterator()
 {
 	if (--p->ref == 0)

src/platform/StdFile.h

@@ -126,6 +126,7 @@ class DirectoryIterator
 public:
 	DirectoryIterator(const char * dirname);
 	DirectoryIterator();
+	DirectoryIterator & operator = (const DirectoryIterator &);
 	DirectoryIterator(const DirectoryIterator &);
 	~DirectoryIterator();