Check if document already published

[M-C-McGrath]

Currently the publish function only sends documents updated since it was last run. But someone could choose a different set of documents or fields to publish. So, instead, the following should be checked-

1. Publication date
2. Document published
3. Fields document published with

The publication date should be used if the document was already published WITH the same fields. If it hasn't been updated and is same field combo, document should not be published.

If it doesn't match and the document matches publication query, it should be resent. If the document wasn't published, it should be republished.