Delete the same shipping class from backend library
Clear the table name error in tax model
Clear the notice error in the get_quote method of shipping
class
Refactor the shipping module class

-- Make it as a abstract class
-- Add the quote methods abstract method
-- Add the shared quote method
Adjust separated shipping modules

-- Remove the quote method because there is the new parent 
quote method shared by them

-- Apply the abstract quote_methods 

-- Adjust the code format
Adjust the code formate of parent shipping module class
update the module separator from - to _
Remove the order totals and shipping classes from admin 
libraries because it is possible to share the classes in the
store front