PIFile::skip() method and PIFile::isEnd() fix for read-only

libs/main/io_devices/pifile.h

@@ -107,6 +107,9 @@ public:
 	
 	//! Move read/write position to text line number "line"
 	void seekToLine(llong line);
+
+	//! Skip "bytes" bytes (move position next to "bytes" bytes)
+	void skip(llong bytes);
 	
 	//! Read one char and return it
 	char readChar();
@@ -295,9 +298,11 @@ protected:
 
 private:
 	PIString strType(const PIIODevice::DeviceMode type);
+	void _init();
 
 	PRIVATE_DECLARATION(PIP_EXPORT)
 	int ret, prec_, fdi;
+	llong _size;
 	PIString prec_str;
 
 };