Support of importing PDFs with multiple papers

[koppor]

A PDF may contain multiple papers. This should be supported by the importer somehow. The user should not have to split the PDF by himself.

Example

http://domino.watson.ibm.com/library/CyberDig.nsf/1e4115aea78b6e7c85256b360066f0d4/b7ed36faf73949a4852581e7006b2a55!OpenDocument&Highlight=0,summersoc

Here also the direct link to the PDF: http://domino.watson.ibm.com/library/CyberDig.nsf/papers/B7ED36FAF73949A4852581E7006B2A55/$File/rc25670.pdf