New German translation of the metadata schema documentation (v2.2)
Merge branch 'master' of github.com:datacite/schema
Merge branch 'master' of github.com:datacite/schema
Executed all remaining changes for v3.0:

- Changed date of version update in all files
- Added xml:lang to subject
- DescriptionType: Deleted "PublicationPlace", added "Methods"
- relationType: added "HasMetadata" & "IsMetadataFor"
- relatedIdentifierType: added "PMID"
- dateType: added "Collected"; deleted "StartDate" & "EndDate"
- contributorType: added "ResearchGroup" & "Other"
- resourceType: added "Audiovisual", "Workflow" & "Other"; deleted "Film"
- resourceType: added new attributes "relatedMetadataScheme" & "schemeURI"
- added geoLocation