Merge pull request #271 from personalrobotics/feature/named_config_list

Adding ability to get a list of named configurations.

Author: mkoval

src/prpy/named_config.py

@@ -112,3 +112,9 @@ def get_configuration(self, name):
             return self._configs[name]
         else:
             raise KeyError('There is no configuration named %s.' % name)
+    
+    """
+    : return known_configurations: A list of named configurations
+    """
+    def get_configuration_list(self):
+        return self._configs.keys()