add contracts to location-formatting functions,
and make sure those functions convert their inputs to strings,
and fix a documentation bug in `techrpt-location`
These commands work like natbib's citeauthor and citeyear commands,
and facilities making possessive citations. For example:
> Thanks to @(cite-author foo)'s (@(cite-year foo)) paper on stuff...
These identifiers are added with `define-cite` as keywords, and thus
can be omitted with no downside for backwards compatibility.
@(define-cite cite citet generate-bib
#:cite-author cite-author
#:cite-year cite-year)
Also in this commit:
* Add documentation.
* Add tests for autobib
* Bump version and add history.
The function bound to `make-my-notes` by `define-footnote` (as in:
```
(define-footnote my-note make-my-notes)
```
) now produces a part with the `unnumbered` style.
This way, footnote sections can go between any two sections on a page
without upsetting the section numbers.
