Feature request: Check before reprocessing

some checks might be (for example):

(a) that there is not already a copy of the item in the republish directory
(b) that the item is not egregiously malformed (so it should at least have a scandata and jpgs)

The checks have to be very simple and fast to perform, so that the gui is capable of them without interfering with its responsiveness.

But both the checks above would be (they just involve looking at the filesystem).

If there are duplicate ids, we want to block people from proceeding unless they adress the duplicate items. Here's what I think that entails:

Everything is blocked except 1) the ability to peek and an item (for investigation) 2) deletion.

Here's one idea on how this would work --

   * The republisher links would be a different color (perhaps red)
   * Clicking the republisher link would give the user the dupe-item prompt, asking them to investigate and fix
   * Likewise, "reprocess" wouldn't work
   * Peek, however, should work. This allows people to assess which copy they'd like to keep