Issue #1176930 by mikeryan: Renamed migrate-destinations to migrate-mappings, enhanced to export to CSV

Smarten --all so it can take a value indicating which Migration to start from. Then the remaining on the list are processed.

Add migrate-needs-update drush command. Reimport records where needs_update=1. This command is only needed when your Drupal DB is on a different DB server from your source data. Otherwise, these records get migrated with just migrate-import.

Change mssql.inc so that its fetch method replaces :criteria placeholder with either an idlist or a highwater or 1=1 depending on whether an idlist was passed inot the request. Needed for reprocessing needs_update=1 records on migrations that also use highwater ... Includes minor drush integration fix and table_copy plugin fix when the import has no records changed

Move lookup cache reporting to a progress message. Only shows on debug level. No need to wait for end of all migrations.

Add back the LookupDestinationID cache. Report on its hit rate in drush import. Migrations need to do nothing special to take advantage.