Erronous key signatures in regression test

[Heikki Johannes Junes]

The accidentals are not deal the right way in the case of
quarter-accidentals. This can be seen in two files:

  input/regression/key-signature-scordatura.ly
    1) signature eih,     no natural sign for e
    2) signature gis+eeh, no natural sign for e and g

  input/regression/keys.ly
    1) signature eeh+bisih+ges, here there is natural sign for e !?

The behavior is different in the two cases. The default output
behavior should not produce erronous notation, therefore
accidentals should be present in both examples mentioned above.

Greetings,

  Heikki Junes