Xgrid Agent for Java

Many changes (may break things).

The temporary working directory and scripts are now stored in a local directory, because some platforms periodically clear out the system temporary directory. This change will prevent agents from losing data on long-running tasks. There has also been some more code cleanup.

Some optimizations were made to a few key parts of the code. There were also a few bugfixes.

A bug in parsing of command line arguments was
fixed. Two null pointer exception bugs were fixed.
A threading issue was fixed. Some fixes suggested
by PMD (http://pmd.sf.net) were implemented.