Add TextSymbolizer.name in python bindings.

Refs #1482.

bindings/python/mapnik/__init__.py

@@ -698,6 +698,18 @@ class PythonDatasource(object):
         return itertools.imap(make_it, features, itertools.count(1))
 
 class _TextSymbolizer(TextSymbolizer,_injector):
+    @property
+    def name(self):
+        if isinstance(self.properties.format_tree, FormattingText):
+            return self.properties.format_tree.text
+        else:
+            return None # This text symbolizer is using complex formatting features.
+                        # There is no single expression which could be returned as name
+
+    @name.setter
+    def name(self, name):
+        self.properties.format_tree = FormattingText(name)
+
     @property
     def text_size(self):
         warnings.warn("'text_size' is deprecated, use format.text_size",