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

Issue #2349991 by fago, Xano, amateescu: Provide a trait for categorizing plugin managers and use it for conditions and actions

Issue #2277981 by tim.plunkett, EclipseGc, fago: Provide a service for handling context-aware plugins.