Small improvements in facets.
Merge remote-tracking branch 'wf4ever/develop' into develop

Conflicts:
	src/main/java/org/purl/wf4ever/rosrs/client/search/Facet.java
	src/main/java/org/purl/wf4ever/rosrs/client/search/FacetValue.java
Tests fixed.
Merge branch 'develop' of github.com:wf4ever/rosrs-client-common into develop

Conflicts:
	src/test/java/org/purl/wf4ever/rosrs/client/TestUtils.java