#136 Import/Clone submissions appear as NewPub in moderator queue

[Ahasuerus]

"Import contents" and "Clone publication" submissions appear as "NewPub" in moderator queue. The problem is that internally Import/Clone submissions are handled as a "ClonePub" sub-type of the "NewPub" type of submissions. The Moderator Queue screen can only see that the submission is a NewPub, not what it's sub-type is. We will need to either make the Moderator Queue display logic smarter about checking sub-types or create a new submission type (or types) for "Imports" and "Clones"

[Ahasuerus]

Also added "AddPub" and "ClonePub" to submission types.