Fixed Servlet-mapping

Changed:
+ Path relative to root of webapp i.e. localhost:8000/eFoods/
(might have to change project name and root context [right-click proj ->
properties -> web project setting])
+ Welcome-file points to FrontServlet
+ Above also fixed weird bug to do with context path causing res not to
load
+ CategoryServlet -> ProductServlet
+ Category.jspx -> Product.jspx
+ Edited Bootstrap.css which previously caused loading of an unreachable
css resource

Added:
+ Main Product model used to communicate with DAO

To-do:
+ Remove DAO init in context since Product model will already do this