DOI and validation: devel sprint 2017-04

[jefferya]

What's in here:

• DOI additions
• validation errors identified by OpenArchives.org validator and oai-pmh validator

Addresses:

• https://github.com/ualbertalib/HydraNorth/issues/1279
• https://github.com/ualbertalib/HydraNorth/issues/1295
• https://github.com/ualbertalib/HydraNorth/issues/1340
• https://github.com/ualbertalib/HydraNorth/issues/1347
• https://github.com/ualbertalib/HydraNorth/issues/1348
• https://github.com/ualbertalib/HydraNorth/issues/1351
• https://github.com/ualbertalib/HydraNorth/issues/1354