Added the User stuff
JavaDocs and regular notes are all over there. Can also answer questions
in lab or in class tomorrow. 
Some of it obviously has errors because it has a few references to
MenuItem and Account, classes that are not present as of yet.

Bear in mind, I am relatively new to Java, so my implementation may not
be the best or seemingly most intuitive. It all should work, and it
seems the best way to do things to me.

I'm sure the majority of the groundwork here is good.
Merge branch 'master' of
file:///C:\Users\Garrett\Documents\GitHub\Banking
User Stuff Added

I added Users, Customers, and BankEmployee and the BankEmployeeRole.
Look at the commit on March 28 and read my green notes.