Added code to use the 'processor' attribute in a page's top-level <fragment> to pick the python function to process the file's xml.
19mmCCMount now uses the photoNav mechanism.
Formatting not 100%. Margins not calculated/set.
Need to code for multiple lines of nav images.
Fixed CSS bug.
Added code to correctly set the width and height for photos.
First pass at line-breaking the nav-images.
Appears to be a margin error.
Photo nav seems complete.