Update parser and sum
Check #5 mostly completed

Need to do return by reference checks
Merge branch 'check5'

Conflicts:
	src/AndOp.java
	src/BitwiseOp.java
	src/BooleanOp.java
	src/BwAndOp.java
	src/BwOrOp.java
	src/OrOp.java
	src/XorOp.java
	src/parser.java
	src/sym.java