Created model + method name changes (updated)

Created classes to model the chat rooms.
Overrode equals and hashcode in ChatRoomInfo
Made some changes to method names in ChatManager to reflect new hungarian prefixes.
introducing new hungarian prefix, crm -> ChatRoomModel
Removed ChatRoomInfo from ChatRoomModel (update)

AddedFiles:

HallwayModel.java - contains map from cri to crm, and relevant operations.
ChatRoomModel.java - contains set of users, list of messages, and relevant operations.

Modified Files:

ChatManager.java
ChatRoomInfo.java

SubmittedBy: Cory Shiraishi