Sunlei99

*add vadd vrem vremrange vcard vcount vrange vmerge
*add a test file

note:
*functions added need return type of string to show the Error message
*there's still bugs in vrange and vmerge
*the test file is used to debug the vector commands
我们这个name还是修改叫key好一点? 还有start -> strat_id stop-> stop_id？