Download articles by title

[DASpringate]

Get PMIDs by title to pass to fetch_in_chunks()

[DASpringate]

This is in order to, say, get lists of article titles (e.g. from paper references) and get a list of pubmed objects from them. I previously did this in Python, scraping the pubmed site directly, rather than using Entrez, but I am sure there is a more elegant way of doing this!