Returns a property set on the context.

        :Parameters:
          key
            String key to lookup in the context props dict
          default_val
            Value to return if key is not set on the context props

def get_prop(self, key, default_val=None):
        """
        Returns a property set on the context.

        :Parameters:
          key
            String key to lookup in the context props dict
          default_val
            Value to return if key is not set on the context props
        """
        if self.props.has_key(key):
            return self.props[key]
        else:
            return default_val