… imports

This commit adds the import status screen and connects it to a not-yet-used queue to manage the state of imports.

…n to strange everything through the import queue

1.  Introducing a robust ImportQueueItem to track an import and follow it through the system
2.  Refactored code to extract behaviors out of GameImporter so it's not a god class
3.  Pre compute as much as possible for an ImportQueueItem, such as which systems are valid.
4.  Try to simplify the general logic to 3 steps - compute, move, and import into the DB

Remaining work

1.  Tons of code clean up
2.  Proper handling of conflicts
3.  Proper handling of CDROMs (need to sort to handle M3U -> Cue -> Bin)
4.  Proper handling of directories
5.  Unit tests where applicable
6.  Ensure validity of imports that flow through this new system.
7.  UI for Conflict handling
8.  Validate that archives work properly.
9.  Validate and fix Artwork

…portQueueItem can now contain Children. We also now check the queue (and any child items in the queue) for duplicates. next step is to pre-process the queue to fix up or detect CDRoms properly.

…lated files, if they're in the queue. this will make it easy to move files to the right place all at once later in the process

…for being able to test a basic import through the system

additional code and warning clean up

…er. ideally that's a utility that need not live here

…GameImporter interfaces