Issue #2920394 by tim.plunkett: Field Layout should not alter fields placed into regions it doesn't know about

Issue #2660124 by tim.plunkett, samuel.mortenson, phenaproxima, tstoeckler, yoroy, dead_arm, xjm, Manuel Garcia, EclipseGc, larowlan, DyanneNova, tedbow: Dynamically build layout icons based on well formed config

Issue #2873696 by nvexler, wengerk, gido, Jo Fitzgerald, xjm: Add @internal to core classes, methods, properties to Form Classes

Issue #2901739 by andriyun, Jo Fitzgerald, mfernea, xjm: Fix 'Squiz.Arrays.ArrayDeclaration' coding standard

Issue #2852608 by Manuel Garcia, DyanneNova, markconroy, tim.plunkett, joelpittet, DickJohnson, Scorpid: Review layout CSS and markup

Issue #2870410 by tim.plunkett: Field UI should show fields with unknown regions in the "Disabled" section

Issue #2840832 by tim.plunkett, DickJohnson, yoroy, DyanneNova, webchick: Add Panels layouts to core

Issue #2821191 by tim.plunkett, tstoeckler, jibran: Allow object-based plugin definitions to be processed in PluginDependencyTrait

Issue #2796173 by tim.plunkett, samuel.mortenson, xjm, jibran, effulgentsia, dawehner, swentel, tedbow, phenaproxima, larowlan, yoroy, dsnopek, tacituseu, japerry, webchick, amateescu, aspilicious: Add experimental Field Layout module to allow entity view/form modes to switch between layouts