extensions to DictEng and addition of parallel DictEngBul which is partly imported from Apertium

src/bulgarian/StructuralBul.gf

@@ -63,6 +63,7 @@ concrete StructuralBul of Structural = CatBul **
                     VPresPart    _ => "òðÿáâàëî" ;
                     VImperative Sg => "òðÿáâàé"  ;
                     VImperative Pl => "òðÿáâàéòå" ;
+                    VNoun _        => "òðÿáâàíå" ;
                     VGerund        => "òðÿáâàéêè"
                   } ;
          vtype=VNormal ;