Number of mods:
1) CHREST instances now have a private reinforcement learning theory variable that can be set using a new method in the Chrest class.
2) The private _actionLinks variable for the Node class stores a <Node, Double> HashMap instead of <Node, Integer> to allow for greater reinforcement precision.
3) The Node.addActionLink method now checks that the node passed as a paramater is actually an action node before adding it.
4) Node.reinforceActionLink altered so that it calls the new polymorphic ReinforcementLearning.calculateReinforcementValue method.
5) New ReinforcementLearning class implemented. Class is intended to be generic so that new reinforcement learning theories can be implemented quickly and easily without adding extra reinforcment learning classes to CHREST code.
Altered getReinforcementLearningTheories method to be a static method since the ReinforcementLearning class should never need to be instantiated so it makes no sense to have non-static methods in the class.
Altered getReinforcementLearningTheories method to be a static method since the ReinforcementLearning class should never need to be instantiated so it makes no sense to have non-static methods in the class.
Reinforcement learning theories now exist as enum classes enabling programmers to specify:
1) The expected number of variables to calculate how much a link between two nodes should be reinforced by.
2) The calculation that should be performed to calculate a reinforcement value based upon a particular reinforcement learning theory.
The 'Node.reinforceActionLinks()' method has now been refactored to take advantage of this enum encapsulation too.
Refactored 'ReinforcementLearning.getReinforcementLearningTheories()' so it is a static method.
1) Refactored 'ReinforcementLearning.getReinforcementLearningTheories()' so it is a static method
2) Added a new method to 'ReinforcementLearning': 'calculateReinforcementValue', an overridable method that should be overriden for each 'ReinforcementLearningTheories' enum value.
3) Added tests to 'chrest-model-tests.rb' to ensure that the 'Chrest.setReinforcementTheory' method works correctly (entailed a minor change to 'all-chrest-tests.rb' so the new 'jchrest.lib.ReinforcementLearning' class is initialised).
Merge branch 'reinforcement-learning' of https://github.com/mlk5060/chrest into reinforcement-learning

Conflicts:
	target/chrest-4.0.0-alpha-2.jar
	target/classes/jchrest/lib/ReinforcementLearning.class
Removed unnecessary imports in jchrest.lib.ReinforcementLearning
Added testing for adding action links, reinforcement values on these links and implementations of reinforcmenet theories.
Refactored 'setting reinforcement learning theory' test suite'.
Removed all debugging code fragments and performed some minor refactoring to class methods concerned with reinforcement learning.