This (minuscule) patch allows to pass a relative (to the buffer's
default directory) file name to denote the CSL style file.

Rationale : this allows the use of "one-of" styles for "one-of"
projects without overloading a defailt CSL style directory (which may
or may not exist on a given system : think JabRef users...). Also
useful for hacked CSL files specific to a given project.

For the same reasons, when the named filename exists both in the
central CSL file and the buffer's default directory, the latter is
retained.

HTH,

PS : Note that I have already transferred my rights to GNU for emacs-
related works.

--
Emmanuel Charpentier