add back bonnes-ondes import command, for completeness

add back bonnes-ondes import command, for completeness

Original history:

commit 6c4a2e9505cd2614f0151850f8f6b5047510e6dc
Author: Frédéric Péters <fpeters@0d.be>
Date:   Sat Jul 21 19:06:21 2018 +0200

    bonnes-ondes: add support for manual audiobank references

commit f505a6da27b6d704cac250e59e26faa14ee07754
Author: Frédéric Péters <fpeters@0d.be>
Date:   Sat Jul 21 17:35:27 2018 +0200

    bonnes ondes: handle unicode image filenames

commit fe79eabdec8eebee03565a807cae260643654290
Author: Frédéric Péters <fpeters@0d.be>
Date:   Sat Jul 21 16:38:26 2018 +0200

    bonnes-ondes: switch importer to textile for formatted texts

commit 173290ee8352efbdc7cc079e3862707328ae3ce5
Author: Frédéric Péters <fpeters@0d.be>
Date:   Sat Jul 21 13:42:22 2018 +0200

    add command to import from bonnes ondes export