Regler för leftChild och rightChild (isValidLeftChild och
isValidRightChild metoder) inlagda
Merge branch 'master' of
https://github.com/Karl-Queckfeldt/HelloCompiler.git

Conflicts:
	src/node/Arithmetic.java
	src/node/Comparison.java
	src/node/Conditional.java
	src/node/Equal.java
	src/node/Greater.java
	src/node/If.java
	src/node/Lesser.java
	src/node/Minus.java
	src/node/Plus.java
	src/node/UsageExample.java
	src/node/While.java