CheckBalance/Redistribution debugging part 1: Minor changes to the balance checking algorithm.

CheckBalanceRequest.java
* now it stores the total size of its subtree

D2Tree.java
* Added a line so that the simulation can be completed.

D2TreeCore.java
* Removed all time references in printed messages
* Modified all calls to the CheckBalanceRequest constructor to suit the new format.
Balance checking bug fixes

D2Tree.java
* Decided to remove the pendingQueries-- line once again because it prematurely stopped the simulation.

D2TreeCore.java
* Added a directory to keep the log files in.
* Messages are now stored in files to better trace the route of each operation.
* Added a few more messages.
* Fixed a bug in forwardGetSubtreeSizeRequest() which would abruptly cut the balance check short instead of forward the message to the parent.
* Fixed the algorithm that determines the size of the subtree in forwardCheckBalanceRequest.
* Grouped forwardCheckBalanceRequest checks by node status. (One big if clause for leaves and another for non-leaves).