When citing subentry, use also the op. cit. for the title of the main entry


Maïeul Rouquette - 2015… - LPPL 1.3, from Paul Stanley 2014 (http://tex.stackexchange.com/a/172777/7712)

http://latex-project.org/lppl/lppl-1-3c.html

Feature requests and bug reports can be made in https://git.framasoft.org/maieul/biblatex-opcit-booktitle/issues