Added Scheduled Task so DataImporter could be run as a Scheduled Task within Sitecore
Tweaked the template fields and the SQL Data Importer to allow for:
 - Deltas Only (appends a Where Create Date field > the Last Run of the Scheduled Task)
 - Default Connection String for when the Importer is run from a Scheduled Task instead of the Data Importer Tab
 - Overwrite Item to force an overwrite or if unchecked than a new version is created
 - Search Index - to be used if the process is to use Lucene to find the existing item instead of the Axes approach which could take a long time if there are a lot of Items, or if the Parent folder is a Bucket
 - Missing Items Query is used to determine what items have been deleted since the last sync
 - History Snapshot Query is used to persist the state of items since the last sync to assist with the Missing Items Query (to determine what items have been deleted)