Update Play and Diagrams

Play can be destroyed now,
Updated the Class Diagram Core Logic part
Implementated the first draft of the following classes
1) MapItem
2) MapPath
3) MapPoint
4) MapValidator
5) PlayManager
6) Road

Note:the method reaffect() of class MapItem has been renamed as
updateAffectableValues()
Merge branch 'master' of https://github.com/zhaozheid/CCD_SOEN6441_TD.git
Merge remote-tracking branch 'upstream/master'