import MeSH keywords in PubMed

[simon]

see ​http://forums.zotero.org/discussion/1236/pubmed-should-import-mesh-index-keywords/#Item_1

looks like this shouldn't be too difficult; sample XML at ​http://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pubmed&id=17548746&rettype=xml

[mikowitz]

(In [1732]) -Closes #744. PubMed translator imports MeSH keywords

[simon]

(In [6198]) closes #1099, Add cancel button to Edit Bibliography
closes #744, Select multiple items/entire collection in edit bibliography dialog

• adds "Cancel", "Revert", and "Revert All" buttons to edit bibliography dialog
• permits multiple item selections in edit bibliography dialog
• removing items in the edit bibliography dialog now leaves the citations intact, but removes them from the document

[simon]

Ignore above—intended target of commit message was #774.