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

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

Issue #2140511 by alexpott, Gábor Hojtsy, swentel, babruix, ohthehugemanatee, jessebeach, Berdir: Configuration file name collisions silently ignored for default configuration