added support for wchar_t file paths and more stable windows builds

include/Athena/FileReader.hpp

@@ -14,6 +14,9 @@ class FileReader : public IStreamReader
 {
 public:
     FileReader(const std::string& filename, atInt32 cacheSize = (32 * 1024));
+#if _WIN32
+    FileReader(const std::wstring& filename, atInt32 cacheSize = (32 * 1024));
+#endif
     virtual ~FileReader();
     inline const std::string& filename() const
     {return m_filename;}
@@ -31,6 +34,9 @@ public:
     void setCacheSize(const atInt32 blockSize);
 protected:
     std::string  m_filename;
+#if _WIN32
+    std::wstring m_wfilename;
+#endif
     FILE*        m_fileHandle;
     std::unique_ptr<atUint8[]>    m_cacheData;
     atInt32     m_blockSize;