Initial BibTeX/DOI citation support in tools and histories.

Allow tool authors to specify citations using a DOI or BibTeX (either by pointing at a BibTeX file in the tool directory or by embedding bibtex entries right in tool citation blocks).

These citations will appear at the bottom of the tool form in a formatted way but the user will have to option to select RAW BibTeX for copying and pasting. Likewise, the history menu now has an option allowing users to aggregatesuch citations across an analysis a comparable list of citations.