Tree-building language

Specification.txt

* The language will represent a tree. Each node can have zero or more children.
It will look like this text (tabs matter):

Root
	A
		B
			C
			D
			E
		F
		G
	H
	I



* Each node is a text like "Root", "A", "B"...
* Each node have has as children all the nodes that have a n+1 level of indentation. For example, the children of node "Root" are "A", "H" and "I"
* Indentation is a tab character