Issue #1956134 by smustgrave, dawehner, larowlan, jibran, jbloomfield,...

Issue #1956134 by smustgrave, dawehner, larowlan, jibran, jbloomfield, lokapujya, Oscaner, elachlan, mgifford, olli, srilakshmier, Manuel Garcia, Nitin shrivastava, afeijo, alexpott, jgeryk, garphy, grisendo, jessebeach, xjm, joachim, tim.plunkett, andypost, Wim Leers, EclipseGc, damiankloip, benjy, klonos: Provide helpful editing links on "admin/structure/block" for deriver blocks (menu, views, block content, etc.)