[search-api] Allow shorthand for fields (attribute shorthand already supported)

git-svn-id: http://code.djangoproject.com/svn/django/branches/search-api@3645 bcc190cf-cafb-0310-a4f2-bffc1f526a37

Author: exogen

django/contrib/search/base.py

@@ -93,6 +93,8 @@ def __init__(self, path, model, fields=None, attributes=None, namespace=None, **
         """
         if fields is None:
             fields = []
+        elif isinstance(fields, basestring):
+            fields = [fields]
         if attributes is None:
             attributes = kwargs
         else: