encog-java-core #192: ColumnDefinition: default index should be -1


Set default index for ColumnDefinition to -1. 

Summary: The former default value was 0, which is a real column index but usually the wrong value. Setting the default to -1 guarantees that the right value will be looked up in the absence of ColumnDefinition.setIndex().

More detail:  https://github.com/encog/encog-java-core/issues/192 

All unit tests are green after the change.