Fixed problem with template not actually appearing in Processing Modes drop-down when built and installed.

Current template when built and installed was not actually showing up in Processing Modes drop-down. Found out (after much hair-tearing) that this is because lib.name in build.xml was not the same value as the subclass of JavaMode.

Fixed this problem, and updated the readme to help other people who run into this problem. 

Tested in Processing 2.0.3.