StudentRegistrationSystem
Updated class to use single instance.
Added check for Logged in/out state and Options list for Logged in
state.

Console
Added additional abstract methods.

NewStudentAccount
Moved String values to Constants class.

Login
Added fields for Student and login state.
Merge branch 'master' of https://github.com/bcrews/Student_Registration

Conflicts:
	data/Student.txt
	source/x464010/teamb/srs/Constants.java
	source/x464010/teamb/srs/NewStudentAccount.java