Refine PubMed query builder

[kofiav]

Instead of selecting a text file containing a list of authors, it would be better if users could:

• Paste in a list of authors
• Select from a list of fields where each field is a descriptive word indicating its purpose or use-case (see http://www.ncbi.nlm.nih.gov/pubmed/advanced)

Also, it would be useful if the feature could be relocated from Apps.Social Network to the main user panel as this would make it more visible to users.