column listing for a source dataset implemented
dataSources json request added
json columns wrapped in object
dataset form implemented
unused request removed
Merge pull request #33 from IDgis/dataset-form

Conflicts:
	publisher-database/src/main/java/nl/idgis/publisher/database/messages/GetSourceDatasetInfo.java
	publisher-domain/src/main/java/nl/idgis/publisher/domain/query/ListSourceDatasets.java
	publisher-service/src/main/java/nl/idgis/publisher/service/admin/Admin.java