Issue #2520540 by alexpott: Enforced configuration dependencies shouldn't have to be repeated in the calculated dependencies

Issue #2452217 by mikeryan, sdstyles, benjy: Rename SourcePluginBase::getIterator() and try make protected

Issue #2561697 by phenaproxima, anavarre, Jeremy: Migration should not choke when the content_node_field table isn't available

Issue #2571499 by benjy, mikeryan, phenaproxima: idMap source and destination id filtering requires keys

Issue #2570541 by mikeryan, phenaproxima: Track simple configuration migrations like normal migrations

Issue #2361093 by mikeryan, dawehner, Devin Carlson, benjy, phenaproxima: Add a rollback functionality to migrate

Issue #2575599 by jaredsmith, joshi.rohit100, dawehner, xjm, alexpott, plach, Berdir, Sutharsan, borisson_, justAChris, stefan.r, joelpittet, Ryan Weal: Remove !placeholder in ContactPersonalTest and Drupal\migrate\Plugin\migrate\id_map\Sql

Issue #2572599 by stefan.r, dawehner, pwolanin, amateescu: Replace !placeholder with @placeholder in a few remaining places

Issue #2560783 by stefan.r, joelpittet, lauriii, Cottser, Sutharsan, kgoel, justAChris, Gábor Hojtsy, dawehner, jhodgdon, effulgentsia, xjm, andypost, googletorp: Replace !placeholder with :placeholder for URLs in hook_help() implementations

Issue #2568775 by dawehner, lauriii, alexpott, joelpittet, xjm: Replace remaining !placeholder for Non-URL HTML outputs only for $e->getMessage()

Issue #2568793 by joelpittet, alexpott, Cottser, klausi: Replace remaining !placeholder for Non-URL HTML when format_size() is involved

Issue #2549783 by lostkangaroo, phenaproxima: RequirementsException gives foreach error when single requirement present

Issue #2559571 by mikeryan, benjy, phenaproxima, quietone: Handle MigrateException consistently during import

Issue #2340401 by benjy, roderik, mikeryan, dawehner, andypost, chx, phenaproxima, larowlan: Fill commented entity during stub comment saving

Issue #2560659 by benjy, phenaproxima, neclimdul: Invalidate the Migration destination plugin when overriding with set()

Issue #2522012 by phenaproxima, mikeryan, chx, benjy: Remove broken idlist handling, replace with more robust exception handling

Issue #2503999 by neclimdul, mikeryan, Berdir, catch, andypost: Large volume entity migrations run out of memory