in __setattr__, name should never be object's variable name

remove context in type_ find's option
find_first_context return AttributError if no results

test/test_cache.py

@@ -136,6 +136,17 @@ def test_reset_cache():
     assert 'u2' not in settings._p_.get_cached('property', c)
 
 
+def test_reset_cache_subconfig():
+    od1 = make_description()
+    od2 = OptionDescription('od2', '', [od1])
+    c = Config(od2)
+    values = c.cfgimpl_get_values()
+    c.od1.u1
+    assert 'od1.u1' in values._p_.get_cached('value', c)
+    c.od1.cfgimpl_reset_cache()
+    assert 'od1.u1' not in values._p_.get_cached('value', c)
+
+
 def test_reset_cache_only_expired():
     od1 = make_description()
     c = Config(od1)