Add support for additional WMS layer metadata properties: multiple MetadataURLs, DataURL, FeatureListURL, Attribution
Adapted default metadata file location
Refactored WmsCapabilities130ThemeWriter, added test

Conflicts:
	deegree-services/deegree-services-wms/pom.xml
	deegree-services/deegree-services-wms/src/main/java/org/deegree/services/wms/controller/capabilities/WmsCapabilities130ThemeWriter.java
Moved merging of LayerMetadata and DatasetMetadata to LayerMetadataMerger

Conflicts:
	deegree-services/deegree-services-wms/src/main/java/org/deegree/services/wms/controller/capabilities/LayerMetadataMerger.java
	deegree-services/deegree-services-wms/src/main/java/org/deegree/services/wms/controller/capabilities/WmsCapabilities130ThemeWriter.java
	deegree-services/deegree-services-wms/src/test/java/org/deegree/services/wms/controller/capabilities/WmsCapabilities130ThemeWriterTest.java
Adaptations after cherry-picking
Better separation of metadata merging concerns from XML serializing concern

Conflicts:
	deegree-services/deegree-services-wms/src/main/java/org/deegree/services/wms/controller/capabilities/ThemeMetadataMerger.java
	deegree-services/deegree-services-wms/src/main/java/org/deegree/services/wms/controller/capabilities/WmsCapabilities130ThemeWriter.java
	deegree-services/deegree-services-wms/src/test/java/org/deegree/services/wms/controller/capabilities/WmsCapabilities130ThemeWriterTest.java
Splitting the different aspects of theme/layer/metadata merging

Conflicts:
	deegree-services/deegree-services-wms/src/main/java/org/deegree/services/wms/controller/capabilities/theme/DatasetMetadataMerger.java
More tests

Conflicts:
	deegree-services/deegree-services-wms/src/main/java/org/deegree/services/wms/controller/capabilities/theme/DatasetMetadataMerger.java
	deegree-services/deegree-services-wms/src/test/resources/org/deegree/services/wms/controller/capabilities/theme/wms130_layer_full.xml
Moved ScaleDenominator merging to LayerMetadataMerger

Conflicts:
	deegree-services/deegree-services-wms/src/main/java/org/deegree/services/wms/controller/capabilities/theme/DatasetMetadataMerger.java
Added AuthorityURL handling
Added exporting of wms:Attribution
Added exporting of wms:DataURL and wms:FeatureListURL
Added XML validation to test
Added requestable attribute to theme identifier to allow metadata attachement to unrequestable layers

Conflicts:

	deegree-core/deegree-core-theme/src/main/java/org/deegree/theme/persistence/standard/StandardThemeBuilder.java
Fixed compile errors
Fixed handling of explicit MetadataURLs
Reworked WmsCapabilities111ThemeWriter, added keywords to dataset metadata configuration
Fixed NPE in MetadataUrl-Template handling
Merge pull request #450 from gritGmbH/3.4/improvement/wms-extended-layer-metadata

Extended WMS Layer Metatadata