Store page numbers in Page classes

Although the document class keeps the page number, the sub pages may
need to know the page number as well. For example X/27 packets
contain relative magazine numbers which need the current page number
to calculate the actual page numbers referenced.

pagebase.h

@@ -37,6 +37,9 @@ public:
 	PageBase(const PageBase &);
 	~PageBase();
 
+	int pageNumber() const { return m_pageNumber; }
+	void setPageNumber(int);
+
 	QByteArray packet(int, int=0) const;
 	bool packetNeeded(int, int=0) const;
 	bool setPacket(int, QByteArray);
@@ -57,6 +60,7 @@ public:
 	bool setPacketCoding(PacketCodingEnum);
 
 private:
+	int m_pageNumber;
 	bool m_controlBits[8];
 	PageFunctionEnum m_pageFunction;
 	PacketCodingEnum m_packetCoding;