reduce runtime.concatstrings in SimpleVar.AppendVar
reduce runtime.concatstrings in SimpleVar.AppendVar

pombredanne/kati,dalinaum/kati,dalinaum/kati,shinh/kati,danw/kati,shinh/kati,google/kati,pombredanne/kati,danw/kati,shinh/kati,google/kati,google/kati,danw/kati,colincross/kati,colincross/kati,dalinaum/kati,pombredanne/kati,pombredanne/kati,danw/kati,colincross/kati,pombredanne/kati,dalinaum/kati,shinh/kati,danw/kati,shinh/kati,colincross/kati,pombredanne/kati,danw/kati,dalinaum/kati,colincross/kati,colincross/kati,google/kati,google/kati,shinh/kati