model cleaning
Merge branch 'M6' of https://github.com/CS2340/BankNote into M5

Conflicts:
	src/JUnit/FileIOTest.java
	src/com/example/banknote/model/RegisterHandler.java
Merge branch 'M6' of https://github.com/CS2340/BankNote into M6
bryan's recent update
Merge branch 'M7_temp' of https://github.com/CS2340/BankNote into M7_temp
singletons added;
Merge branch 'M7_temp2' of https://github.com/CS2340/BankNote into M7_temp2

Conflicts:
	src/com/example/banknote/model/addTransactionHandler.java
	src/com/example/banknote/view/AddFinAccount.java
	src/com/example/banknote/view/AddTransScreen.java