Gregofacsimil + rsigns according to H, modern text

Added nabc for verse. Verse is close to H and prosodically identical

Switched verse text to H (like Sandhofe did), the difference is acceptable.

Backported dcrochu's changes

Switched the text back to the BR text because the adaptation is trivial

Final call: we apply the BR text fully to the V/, meaning autem+vero, implying a slight change to the neumes to remove the liq.