add interface SniperCollector
add unittest addNewSniperToCollectionAndThenJoinAuction
pass unittest addNewSniperToCollectionAndThenJoinAuction
move SwingThreadSniperListener to ui package
let SniperTableModle implement SniperCollector
add SniperPortfolio for recording sniper activities
let SnipersTableModle implement PortfolioListener
add serial code