Divide ratings by 2 when used in a template.

src/calibre/ebooks/metadata/book/base.py

@@ -625,6 +625,8 @@ def format_field_extended(self, key, series_with_index=True):
                 res = res + ' [%s]'%self.format_series_index()
             elif datatype == 'datetime':
                 res = format_date(res, fmeta['display'].get('date_format','dd MMM yyyy'))
+            elif datatype == 'rating':
+                res = res/2
             return (name, unicode(res), orig_res, fmeta)
 
         return (None, None, None, None)

src/calibre/library/save_to_disk.py

@@ -198,7 +198,6 @@ def get_components(template, mi, id, timefmt='%b %Y', length=250,
     for key in custom_metadata:
         if key in format_args:
             cm = custom_metadata[key]
-            ## TODO: NEWMETA: should ratings be divided by 2? The standard rating isn't...
             if cm['datatype'] == 'series':
                 format_args[key] = title_sort(format_args[key], order=tsorder)
                 if key+'_index' in format_args: