Performance optimisation changing "object.properties.containsKey(propertyName)" to (object.hasProperty('column1') ? true : false);

This uses Groovy Native methods to check if the property is there or not. This saves a hashMap having to passed back. This can have a saving especially where the object references other Objects.  On the shouldFillRowAtPosition test I getting an improvement from 1.891 to 0.447. On the other tests I am seeing a performance increase as well.

Changes to be committed:
modified:   src/groovy/pl/touk/excel/export/getters/PropertyGetter.groovy