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
uid实际上是当前访问用户uid,　我们不如叫visit_uid? 这样好像api看起来就容易理解？