Split facilitator servlet for easier maintenance

[averbraeck]

The FacilitatorServlet class is over 2000 lines now. It can be split over multiple smaller classes with static methods (almost all methods of the servlet class are static already).

[averbraeck]

The FacilitatorServlet has been split into the following classes:

• ContentFlood (handling dice rolls)
• ContentNewRound (handling the creation of a new round)
• ContentTaxes (handling tax calculation)
• PopupBuyServlet (handling the popup for allowing/rejecting of house buy)
• PopupSellServlet (handling the popup for allowing/rejecting of house sell
• PopupStayServlet (handling the popup for allowing/rejecting of house stay)
• TablePlayer (filling the player information tables)
• TableHouse (filling the house information tables)
• TableNews (filling the news table)
• TableFlood (filling the flood information table)

The FacilitatorServlet itself just handles the state machine and the popups related to the state progress with warnings about the number of active players and players' progress.