UML diagrams with higher resolution and different font size added. Complete UML diagram: high resolution vertical version for print and scalable version added. Adjusted image widths for screen and print media. Details see issue 113, https://github.com/linked-statistics/disco-spec/issues/113
Conflicts regarding discovery.html resolved.
JPGs reverted

Merge branch 'master' of https://github.com/linked-statistics/disco-spec

Conflicts:
	diagrams/access-rights-statements-and-licenses.jpg
	diagrams/concept-review.jpg
	diagrams/concept.jpg
	diagrams/data-file-coverage.jpg
	diagrams/data-file.jpg
	diagrams/datatype-properties.jpg
	diagrams/descriptive-statistics.jpg
	diagrams/logical-data-set-coverage.jpg
	diagrams/logical-data-set.jpg
	diagrams/object-properties.jpg
	diagrams/overview-data-set.jpg
	diagrams/rdfs-resource.jpg
	diagrams/representation-review.jpg
	diagrams/representation.jpg
	diagrams/study-coverage.jpg
	diagrams/study-metadata.jpg
	diagrams/study-universe.jpg
	diagrams/variable-and-variable-definition.jpg
	diagrams/variable.jpg
	diagrams/versioning-information.jpg
	discovery.html