Delete service needed to simplify client usage

[jmoore]

Currently it is quite difficult to delete an image requiring a query roughly of the form:

    public final static String IMAGE_QUERY = "select i from Image as i "
            + "left outer join fetch i.pixels as p "
            + "left outer join fetch p.channels as c "
            + "left outer join fetch c.logicalChannel as lc "
            + "left outer join fetch c.statsInfo as sinfo "
            + "left outer join fetch p.planeInfo as pinfo "
            + "left outer join fetch p.thumbnails as thumb "
            + "left outer join fetch p.pixelsFileMaps as map "
            + "left outer join fetch map.parent as ofile "
            + "left outer join fetch p.pixelsDimensions as dim "
            + "left outer join fetch p.settings as setting "
            + "where i.id = :id";

which we obviously shouldn't require each client develoepr to enter.

There is an issue with exactly what the semantics are (to be defined here later), but we will most likely also want to allow for some customization of the delete process. (e.g. does a particular site want OriginalFiles to be deleted when an Image is deleted?)

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See also : #587

[jmoore]

r2033 Has a fully working implementation. Leaving this open for further testing from the client-side, definition of the semantics, and possible API changes.

[jmoore]

No word for or against. Closing. Either reopen or open specific tickets for API changes.