Add instructions on compiling java

[aterrel]

@gvidaver added a java example, but the makefile tells me to run ant and setting JAVA_HOME doesn't seem to find jni.h.

Please add instructions to compile the java example or a script over at darpa-xdata/xlang-vm

[gvidaver]

OK I added a brief update to the wiki there about java building and paths : https://github.com/darpa-xdata/xlang-vm/wiki/Java-notes not much there yet though.

[aterrel]

@gvidaver Thanks! Can you add to the deployment scripts the pieces you need on the hardware (eventually).