2 issues with Concert Pitch

While making an arrangement for Big Band, and using the Concert Pitch function, I discovered two bugs:

1. When adding a new instrument (not tuned in C, for example Bb Trumpet) to the score, with Concert Pitch enabled, the newly added instrument does NOT have the right key. Workaround: turn off the Concert Pitch option before adding an instrument.

2. When adding a new, C-tuned, instrument to the score, it does not inherit the key signatures of the whole arrangement, but it creates a staff for the instrument without key signature (hence in C major). Workaround: add the key signature (Bb major) manually to the staff.

Scenario:
- I started with a score for 4 saxophones (2 alt, 1 tenor, 1 bariton), in Bb major (Concert Pitch)
- I added three Bb trumpets, and discovered I needed to turn off Concert Pitch before adding them. After that, it works fine.
- I added one Trombone, and discovered it adds a staff without key signatures. Tried it with the Concert Pitch option enabled or disabled, but that didn't change anything. The I added the key signature manually to that staff, and it solved the issue.