Fixed bug in Helper.fileCopy()
    - Since byte was [1024 * 1024], output was of size 1024*1024
    - Fixed by using write(byte[], offset, length)
Updated PerformanceTests.increasingRangesTest
    - Now contains a larger domain for testing performance
    - Updated corresponding definitions file as well
Added TimeKeeper class to manage time
Moved helper classes used in test package to root of test package
These classes should be moved to their own package in the future
Updated all references to these classes
Multiple constraints on same property, same level need to be merged

Updated condition package to store range of permissible values
and return a single value when required
Fixed bounds beyond limits being included in processBounds
Replaced return statements in Datum.compareTo
    - compareTo was returning 0 for '0 [>|<] 0'
Property class now uses a static initializer

This change forced redesign of the Property class

The biggest change has been that reference is now stored as a
separate Reference instance in many container classes

The reason for this change has been the inability to test
code such as if(def.property().equals(property)), resorting to
string comparisons to achieve the same
Code beautification
Added missing interface method to obtain unionType from conditions

Moved constraint resolution to its own package
    This change separates constraint resolution methods and
    logic from the core WorldTree class

    The idea is to allow pluggable constraint solvers

    A constraint solver can be plugged in by changing the currently
    hard-coded intialization in ConstraintSolver class

Working on brute force constraint solver

Removed some warnings from various files
QueryResolutionEngine now uses CONSTRAINT statement case to handle
constraint queries
Finished implementing brute force constraint solver
    - Tested with simple constraints
Adding 'sample' folder
    - This folder is to contain sample definitions and properties
    - These instances should be integrated into future test cases
Fixed warnings in several packages
Added code for PASSABLE_NORTH and PASSABLE_SOUTH