Bug 10975

This patch and additional files make the following changes to the viewer:

1) Row Header (ie row numbering)
2) Row Height now works. Ie can render different row heights as per the excel 
file
3) Column Widths now works. Ie can render different column widths.
4) Started to add editing functionality. But then added the above, so although 
the beginnings of editing is there it wont change the excel file.
5) Started to add the SVFractionalFormat. At the moment the formatter will 
return 1/1 rather than the correct fraction. The algorithm to produce the 
fraction has not been followed correctly ;-) I will fix this later.
6) Im not sure what else but there probably is more things

Jason Height