Issue #2790111 by neclimdul, mikeryan: DrupalSqlBase doesn't include missing source in requirements exception

Issue #2572801 by alexpott, vprocessor, andriyun, andypost, chishah92, Mile23, attiks, hussainweb, klausi, dawehner, pfrenssen: Fix 'Drupal.WhiteSpace.ScopeIndent' coding standard

Issue #2549801 by quietone, balagan, lostkangaroo, pingers, martins.kajins, phenaproxima, scuba_fly, penyaskito: Improve source provider missing exception message

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2676222 by alexpott, johnrosswvsu: Move MigrationInterface out of the migrate\Entity namspace now they are plugins

Issue #1392754 by tss, justAChris, jhodgdon: Comply with new documentation standards for @file for namespaced class files

Issue #2460529 by alexpott, chx, phenaproxima: Migrations need to use the configuration entity dependency system

Issue #2457887 by prateekMehta, stefan.r, rpayanm, alexpott: Use Utility\SafeMarkup class instead of Utility\String for placeholder(), checkPlain(),format() functions

Issue #2321609 by benjy, dawehner: Fixed Provide a helpful message in case requirements are not met.

Issue #2121299 by andypost, bdone, benjy, penyaskito, chx, claudiu.cristea, damiankloip, gregboggs, InternetDevels, jessehs, jhedstrom, marvil07, mikeryan, pcambra, Xano, YesCT, axoplasm, kgoel, dclavain, jeckman, alvar0hurtad0, Drupali, fastangel, gloob, jhedstrom, joshtaylor, mpgeek, alexpott: Migrate Drupal 6 to Drupal 8

Issue #2213451 by andypost, bdone, benjy, penyaskito, chx, claudiu.cristea, damiankloip, gregboggs, InternetDevels, jessehs, jhedstrom, marvil07, mikeryan, pcambra, Xano, YesCT: Update Migrate API in core