New features

• Filter is added to find content more efficiently.
• Pagination bug fixes.

This module is being used and has been used for quite some time in production.

Would like to get more testing on this so placing it in alpha for now.

This is the initial release.

- Adds optional query parameter forwarding
- Slight code refactor based on community suggestions
- Fixes PHP warning in #3023058
- Adds instructions and help text for Pantheon users as per #3023059. More formal fix in code is TBD.

Exact copy of https://www.drupal.org/project/migrate_source_yml