introduce response handling in the JmsWrapper
revise the portfolio service: temporarily ignore messages from clients; init portfolios at startup (number of portfolios read from conf); simplify portfolio updates (no command and no old quantity)
add conf param (number of portfolios)
change serial version UID
handle the GET_PORTFOLIO_STATUS request (respond with the current status of the portfolio)
add checks on the bought/sold stock
handle buy/sell messages
Update README.md
Update README.md
Merge pull request #2 from valeriocelletti/patch-1

Update README.md
add note about PortfolioMessage
Merge branch 'no-pub-on-demand' of https://github.com/Weswit/Lightstreamer-JMS-example-Portfolio-service-java