'Required:
att --the attribute
value --the value
Returns:
nothing
Logic:
I have to build the branches of the dictionary before I can add
the leaves. (I am comparing a dictionary to a tree.) To achieve
this, I first make a temporary dictionary by extracting either the
inside dictionary of the keyword par or char. This temporary
dictionary is called type_dict.
Next, create a second, smaller dictionary with just the attribute and value.
Add the small dictionary to the type dictionary.
Add this type dictionary to the main styles dictionary.'

def __add_dict_entry(self, att, value):

    if (self.__type_of_style == 'par'):
        type_dict = self.__styles_dict['par']
    elif (self.__type_of_style == 'char'):
        type_dict = self.__styles_dict['char']
    elif (self.__run_level > 3):
        msg = (self.__type_of_style + 'error\n')
        raise self.__bug_handler, msg
    smallest_dict = {}
    smallest_dict[att] = value
    type_dict[self.__styles_num] = smallest_dict
    self.__styles_dict[self.__type_of_style] = type_dict
