Implemented creation of validTime elements
Merge branch '3.4-feature-wfs-temporality-extension' of github.com:occamlabs/deegree3 into 3.4-feature-wfs-temporality-extension

Conflicts:
	deegree-services/deegree-services-wfs/src/main/java/org/deegree/services/wfs/te/DeegreeDynamicFeatureQueryAdapter.java
Fixed regressions of unit tests (after renaming of example query files)
#617: Fixed missing gml:id on TimeSlice