Support adding DOIs for large files

[p-a-s-c-a-l]

When adding a DOI to an existing resource (see #154), the actual data has to be uploaded to zenodo.org. Several files exceed the the maximum size of 100MB per file that is supported by zenodo.org (e.g. Discharge(EHYPE2pt5).zip):

Heads up! We will be launching a new file API which is significant more performant than the current API and which supports much larger file sizes. The current API supports 100MB per file, the new supports 50GB per file.
http://developers.zenodo.org/#deposition-files

Workaround: Instead of uploading the actual file, upload a textfile that contains the url to the file on deltares server.

[p-a-s-c-a-l]

Sanitize Metadata Repository (add to Some-useful-SQL-Scripts).

delete from metadata where type is null;

delete from metadata where id not in 
    (select metadataid from jt_metadata_resource) 
    AND id not in (select metadataid from jt_metadata_relationship);

[ci-cismet-de]

Integrated branch 'feature/156-dois-for-large-files (16c0fd2)' into 'dev (a572e44)' -- Build 6

[ci-cismet-de]

Integrated branch 'feature/156-dois-for-large-files (16c0fd2)' into 'dev (a572e44)' -- Build 7

[ci-cismet-de]

Integrated branch 'feature/156-dois-for-large-files (16c0fd2)' into 'dev (a572e44)' -- Build 8

[ci-cismet-de]

Integrated branch 'feature/156-dois-for-large-files (16c0fd2)' into 'dev (a572e44)' -- Build 9

[ci-cismet-de]

Integrated branch 'feature/156-dois-for-large-files (16c0fd2)' into 'dev (a572e44)' -- Build 10