Integrate harvester, update, and refresh functions into one module

This issue obsoletes #1427404

We need to be able to support the following use cases:

1) Collection is new on Drupal site, user want to harvest all items in a collection. The current approach in the Harvester module is hard to understand and flakey; we need to use the Batch API.

2) Collection has a number of updated items, user needs to refresh these items' metadata on the Drupal site. It should be noted that the item metadata is refreshed automatically on item view if that option is turned on in the CONTENTdm Integration admin settings.

3) Some items have been deleted from CONTENTdm and reloaded, but the originals have Drupal nodes. This is the use case that Refresh Reloaded was intended to address. To keep the link between the original node and the new item, the CONTENTdm item must have a field that is unique to that item, e.g. Dublin Core identifier.

4) Currently, item metadata can be refreshed at the item display (node) by adding /refresh to the end of the node URL or clicking on the 'Refresh' link in the metadata utilities (if user has permission). We should also provide a tool in this new module that allows a user to look up a node by title and then click on a 'Refresh' button.