Added com.collection.range package

This package consists of classes that implement the concept of
Ranges

Consists of two classes that extend the abstract class Range
    - IntegerRange
    - FloatRange

Currently, Ranges allow the following functionality
    - contains
    - intersection
    - add

Range addition currently works only for the same types

PropertyDef.RandomSpec now uses Range class
Updated Parser and WorldTree to reflect this change

WARNING: This patch breaks the existing WorldTree.split method