Create a single Biblio citation programmatically

In running a site that allows a user to input the PMID in through another (unrelated) module, and then use that entry to automatically pull in the Biblio/PubMed citation and populate it with the data. There were a few noticeable issues with the pubmed_integration_import_data and pubmed_integration_load_citation_by_pmid functions which needed correction.

The follow issues are addressed in this patch in order to make it work with Biblio correctly, given that Biblio has had a number of extensive upgrades since this module was last updated.

-The global $user declaration was missing from the pubmed_integration_import_data function. This was causing all citations to pull in as an Anonymous user, despite the code to attach the user id to the biblio node
-The variable biblio_custom3 was being used to store the PMID on a Biblio node. This is fine, but the PubMed link on the Biblio node is looking for the (newly added) biblio_pubmed_id variable, and as such the link would never display because the variable wasn’t being populate. I added this assignment to the node creation.

This should allow those who want to call for a single PMID outside of the Biblio form to do so more easily.