Code cleanup & ant unit test tasks

[GoogleCodeExporter]

I forked the project worked a little on the code, specifically:

* The ant task is now extended to automatically download the depending library 
and offer a unit test task

* The RescaleOP operation got refactored/cleaned up: method&variable names that 
are easier to understand, reduced the total LoC and applying some techniques 
for better readability.

* The Progress system in the main task should be less error prone and easier to 
read.

* I clean out some code quality problems (like mixed indentation and unused 
imports)

Maybe you are interested to take over some of the changes?

https://github.com/martinheidegger/java-image-scaling

Original issue reported on code.google.com by martin.h...@gmail.com on 18 May 2012 at 5:36