Replace ' and " with prime and double prime where appropriate

This includes:
 * ' to mean simply prime, as in E'
 * ' to indicate feet and arcminutes
 * " to indicate inches and arcseconds
Fix miscellaneous problems with quotes

Problems include:
 * missing open or close quotes
 * too much or too little whitespace around quotes
 * misnested double and single quotes
Attempt to deal with spurious single quotes

These would really benefit from checking against the source.
Manually convert leading apostrophes to &rsquo;

These are too messy to handle programatically.
Manually handle an instance of triply nested quotes

To handle this programatically would require a quote stack concept.
Convert ' and " to the appropriate quotes programatically
Use pretty quotes in toc.ncx as well