Generalized numerical hirarchy to match standard hirarchy

We managed to make the hirarchy match the standard hirarchy as you suggested. It looks way nicer now.

One issue I am still not sure about is the naming of the functions `fromIntegerB`, `toIntegerB` and `fromIntegralB`. On the one hand this is conform with the naming scheme used in other places (e.g. `oddB`, `evenB`, `ifB`). But on the other hand all other functions associated with the deep embedded number hirarchy do not have the suffix `B`. I like the thought that one can just replace the standard hirarchy with this one and then use the same numeric expressions as before. So maybe we should rename `fromIntegerB` and `toIntegerB` into `fromInteger` and `toInteger`. But that will raise the question if it might be justified to also changes the names of `fromIntegralB`, `evenB` and `oddB`.