Add x64 platform for Cache.vcxproj

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
Fix missing include file "SmartLibgit2Ref.h"

it needs to be included after git2.h

Signed-off-by: Yue Lin Ho <b8732003@student.nsysu.edu.tw>
Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>