Added Servlet and improved core files

Added:
GetChatLogServlet.java - gets entire chat log from server by http request

Modified:
ChatServerManager.java - renamed from ChatManager.java for less confusion; as a result, references in all servlet classes involving ChatServerManager.java have been updated
Servlets have been updated to use BaseServlets native getParameters method rather that HttpResponse's one directly.

AuthoredBy: colinkho