Log Message:
tex-urlbst{,-doc}: update to 0.9.1

* Changed repository location to heptapod.host (https://heptapod.host/nxg/urlbst)
  (when Bitbucket dropped support for Mercurial).
* Refactoring of the mechanism for configuring the generated .bst file,
  specifically adding the --setting option.
* Added the doiform setting to generate DOIs wrapped in \doi{...}.