Make the field 'title_sort' work. It didn't because of the name mismatch with 'sort'

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

@@ -484,9 +484,12 @@ class Metadata(object):
                 res = self.format_series_index(res)
             return (name, unicode(res), orig_res, cmeta)
 
-        if key in field_metadata and field_metadata[key]['kind'] == 'field':
+        # Translate aliases into the standard field name
+        fmkey = field_metadata.search_term_to_field_key(key)
+
+        if fmkey in field_metadata and field_metadata[fmkey]['kind'] == 'field':
             res = self.get(key, None)
-            fmeta = field_metadata[key]
+            fmeta = field_metadata[fmkey]
             name = unicode(fmeta['name'])
             if res is None or res == '':
                 return (name, res, None, None)

src/calibre/library/field_metadata.py

@@ -259,8 +259,8 @@ class FieldMetadata(dict):
                            'datatype':'text',
                            'is_multiple':None,
                            'kind':'field',
-                           'name':None,
-                           'search_terms':[],
+                           'name':_('Title Sort'),
+                           'search_terms':['title_sort'],
                            'is_custom':False,
                            'is_category':False}),
             ('size',      {'table':None,