Simplify rules when importing/exporting

[kliegr]

Current export generates rules such as

(neck(yes) & axillar(no)) & bone(no) ...

Preferably, this should be exported as

neck(yes) & axillar(no) & bone(no) ...

[kliegr]

Rules are not only exported like this, but also shown in the editor. It would therefore make sense to simplify the rules already when they are imported to the editor.