Skeleton of EMLEvaluator class and MetaDescriptorEvaluator class
Merge remote-tracking branch 'origin/dev'

Conflicts:
	dwca-validator-lib/src/main/java/org/gbif/dwc/validator/structure/evaluator/EMLEvaluator.java
	dwca-validator-lib/src/main/java/org/gbif/dwc/validator/structure/evaluator/MetaDescriptorEvaluator.java