Unify intrahash information available via the API and the webinterface, especially the bibtex export

[Former user]

Reported by dbe: Currently, information about a bibtex's intrahash is available in different formats:

• when exporting bibtex via the webinterface, as part of the biburl={...} field
• when fetching entries via JabRef, as special field intrahash={...}

This has the bad consequence that when someone

1. exports his collection via the web interface
2. imports this bibtex via JabRef's bibtex import feature
3. tries to upload these entries to BibSonomy via JabRef

this will be not possible because JabRef doesn't identify the intrahash part of the biburl-field and tries to create a new entry, which is not possible because this entry already exists.

We should come up with a more consistent solution for this.

[Stephan Doerfel]

This is a problem of our JabRef Plugin. It uses the intrahash to identify posts internally. Thus when a post is changed, and then exported to bibsonomy, then the intrahash is adapted and the post can no longer be matched to its counterpart in jabref.