Custom import/export

[Jonathan Corwin]

Two problems.
1. It isn't possible to transfer individual custom items to and from other machines
2. If you import a songs database, and that database contains say liturgy (e.g. a v1 db) there isn't an easy way of transferring those items to the custom list.

A solution for both: Create an OpenLyrics Import/Export for custom items. Credits would become authors. Other info like verse tags and books etc would get lost on import.