Dear All,

since bibtex and biblatex requires title fields to be in title case
but CSL assumes that they are in sentence-case, citeproc-el converts
title fields in bib(la)tex bibliography databases into sentence-case
before processing them except for entries with an explicit non-English
langid value. Although this seems to be reasonable behaviour, there
were several requests in the last couple of years to make it possible
to turn this conversion off (see, e.g., citeproc issues  #119 and
#142). The attached patch introduces a new custom option to configure
when to perform the conversion.

I'm a bit unsure about naming the option:
Perhaps `org-cite-csl-sentence-case-bibtex-titles-without-langid'
would be more precise but I found it absurdly long and technical, as
most users are probably unaware of the existence of langid fields.

best wishes,
András