Working with references issues

[ollehints]

• Retrieving data by DOI should be more clear to users:
  • The button check / kontrolli should be renamed to "Fill using DOI:" / "Täida DOI abil:"
  • The button should always be visible, and in front of the DOI field.
• In reference list view, when clicking the pdf icon, a popup window should be opened instead of new tab, and for next pdf, a new popup window should be opened (currently the next pdf is opened in the same new window replacing the previous pdf - making it impossible to read/compare two or more pdfs at once). If pdf is opened from the detail view, then it already works in the intended way.
• retrieving data from crossref via DOI should also fill in the abstract
• before getting data via DOI, check if reference with same DOI is already in database - if yes, show a popup with link to the existing recod.

[Erikdzo]

Regarding filling in the abstract. The crossref API returns the abstract using JATS XML and filling the abstract breaks it.

Ex. https://api.crossref.org/works/10.1017/S0016756809990185