Fix cli when used with sf2.4
bug #19 Fix cli when used with sf2.4 (brikou)

This PR was squashed before being merged into the 1.0.x-dev branch (closes #19).

Discussion
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Fix cli when used with sf2.4

`DescriptorInterface` and `DescriptorHelper` have changed (between sf2.3 and sf2.4) so just get rid of these
supersede #18

Commits
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8da19f3 Fix cli when used with sf2.4