Add standard iterator typedefs

Boost 1.55 seem to need these:

/usr/local/include/boost/iterator/iterator_traits.hpp:36:64: error: no type named 'reference' in 'boost::detail::iterator_traits<npge::FileReader::const_iterator>'
    typedef typename boost::detail::iterator_traits<Iterator>::reference type;
...
/tmp/npge/src/algo/ImportBlastHits.cpp:144:5: error: no matching function for call to 'deref'
    BOOST_FOREACH (std::istream& input_file, file_reader_) {

src/algo/FileReader.hpp

@@ -36,6 +36,13 @@ class FileReader {
 public:
     /** Iterator class manages file open/close */
     class const_iterator : public std::iterator<frci_tag, std::istream> {
+    public:
+		typedef std::istream value_type;
+		typedef int difference_type;
+		typedef std::istream* pointer;
+		typedef std::istream& reference;
+		typedef std::forward_iterator_tag iterator_category;
+
     public:
         /** Go to next element */
         const_iterator& operator++();