[wip-cite-new] experimental citeproc-el based activation processor

[András Simonyi]

Dear All,

playing with the new citation API (which is already very impressive
and usable!) I cobbled together an "activation processor" which
fontifies Org citations using citeproc-el generated previews (when the
cursor is elsewhere). It also shows the full references as a tooltip
on mouse-over. Currently everything is very experimental, but if any
of you is willing to give it a try it can be found at
https://github.com/andras-simonyi/org-cite-csl-activate, and, of
course, any feedback is welcome.

best regards,
András