Issue #2448765 by nlisgo, Damien Tournoud, vlad.n, rteijeiro, Berdir, Fabianx, dawehner: Element::children sort order undefined and slower than it could be - This makes tests fail in PHP7

Issue #2364157 by mpdonadio, dawehner, martin107, Berdir, pcambra, naveenvalecha, tim.plunkett: Replace most existing _url calls with Url objects

Issue #2343661 by larowlan, tim.plunkett | xjm: Rename l() to _l() and url() to _url(), and document replacements.

Issue #697760 by sun: Replace getInfo() in tests with native phpDoc + annotations (following PHPUnit).

Issue #2095613 by juanolalla, g.oechsler, grisendo | YesCT: Convert all plugin IDs in local_tasks().yml to 'module_name().foo_bar()' naming convention to match routing convention.

Issue #2095139 by dawehner, pwolanin, kfritsche, YesCT, tstoeckler: Fixed Checking for the active tab should use raw variables.

Issue #2076283 by dawehner, pwolanin, neclimdul: Allow local task plugins on paths with a dynamic value (like a node).

Issue #2050919 by neclimdul, pwolanin, damiankloip, dawehner: Replace local task plugin discovery with YamlDiscovery.

A little bit too much...

This reverts commit aab7094c.

Issue #1864066 by sun, andypost, tim.plunkett: Simplify hook_menu_local_tasks() and MENU_DEFAULT_LOCAL_TASK usage.