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

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

Issue #2504139 by borisson_, Wim Leers, plach, prashantgoel, Fabianx, dawehner, David_Rothstein, effulgentsia: Blocks containing a form include the form action in the cache, so they always submit to the first URL the form was viewed at