add support for nested contexts as described in the "Non-False Values" section…

add support for nested contexts as described in the "Non-False Values" section of http://mustache.github.com/mustache.5.html

examples/nested_context.mustache

+{{#foo}}{{thing1}} and {{thing2}}{{/foo}}{{^foo}}Not foo!{{/foo}}
\ No newline at end of file

examples/nested_context.py

+import pystache
+
+class NestedContext(pystache.View):
+    template_path = 'examples'
+
+    def foo(self):
+        return {'thing1': 'one', 'thing2': 'foo'}

pystache/template.py

@@ -85,6 +85,9 @@ class Template(object):
             elif it and not hasattr(it, '__iter__'):
                 if section[2] != '^':
                     replacer = inner
+            elif it and hasattr(it, 'keys') and hasattr(it, '__getitem__'):
+                if section[2] != '^':
+                    replacer = self.render(inner, it)
             elif it:
                 insides = []
                 for item in it:

tests/test_examples.py

@@ -11,6 +11,7 @@ from examples.template_partial import TemplatePartial
 from examples.delimiters import Delimiters
 from examples.unicode_output import UnicodeOutput
 from examples.unicode_input import UnicodeInput
+from examples.nested_context import NestedContext
 
 class TestView(unittest.TestCase):
     def test_comments(self):
@@ -67,5 +68,8 @@ Again, Welcome!
 * Then, surprisingly, it worked the third time.
 """)
 
+    def test_nested_context(self):
+        self.assertEquals(NestedContext().render(), "one and foo")
+
 if __name__ == '__main__':
     unittest.main()