Liber Hymnarius 2019 (two inconsistencies with Gregofacsimil, one with Hartker on reCESsit) with rsigns from H

LRT corrections by dcrochu.

Require SI, loco DO, ad "FONS aquae". Cf RESP Ecce vidimus eum, ad "SAnati sumus", Benevento 21/126v semitonus indicat. Notandum est quod in RESP Recessit pastor noster, B21/133v, ad "fons" ambiguus est.

Fons: do->si