Issue #2560783 by stefan.r, joelpittet, lauriii, Cottser, Sutharsan, kgoel, justAChris, Gábor Hojtsy, dawehner, jhodgdon, effulgentsia, xjm, andypost, googletorp: Replace !placeholder with :placeholder for URLs in hook_help() implementations

Issue #2429617 by Wim Leers, Fabianx, Berdir, yched, dawehner, effulgentsia, catch, borisson_, jhodgdon, martin107, torgosPizza: Make D8 2x as fast: Dynamic Page Cache: context-dependent page caching (for *all* users!)

Issue #2421503 by lauriii, larowlan, Wim Leers, dawehner, tim.plunkett: SA-CORE-2014-002 forward port only checks internal cache

Issue #2473729 by FMB, darol100, ifrik, ivarlaks, jhodgdon: Review the hook_help for Internal page cache module

Issue #2368987 by Wim Leers, Berdir, Schnitzel, epari.siva, bircher, vijaycs85, likin: Move internal page caching to a module to avoid relying on config get on runtime