Revert "Issue #1331486 by katbailey, chx, sun, beejeebus, amateescu: Move module_invoke_*() and friends to an Extensions class. Broke core tests after commit."

This reverts commit c80c3e18.

Issue #1331486 by katbailey, chx, sun, beejeebus, amateescu: Move module_invoke_*() and friends to an Extensions class.

Issue #1873574 by David_Rothstein: Fixed Cron URL on status report page is no longer an absolute URL.

Issue #1792536 by chx, Berdir, sun, David_Rothstein: Remove the install backend and stop catching exceptions in the default database cache backend.

Issue #1833516 by Berdir, chx, catch, webchick: Add $settings for low-level configuration - move things out of .

Issue #1860778 by plach, tayzlor, Berdir, cosmicdreams: Fixed Provide an upgrade path for date formats.

Issue #937284 by chx, tim.plunkett, Berdir, Damien Tournoud: Fixed DEADLOCK errors on MergeQuery INSERT due to InnoDB gap locking when condition in SELECT ... FOR UPDATE results in 0 rows.

Revert "Issue #1824898 by vijaycs85, ACF: Convert drupal_weight_select_max() variable to CMI system."

This reverts commit cd8dd173.

Conflicts:

	core/modules/system/system.install

Issue #1824778 by vijaycs85, ACF, pcambra, cam8001: Covert css_gzip_compression() and js_gzip_compression() variables to CMI system.

Issue #1571632 by cosmicdreams, marcingy, justafish, chx, KarenS, aspilicious, disasm, swentel, dawehner, rvilar: Convert regional settings to configuration system.

Issue #1559780 by sun: Fixed Remove ban_ip_action() from core. It blocks the currently logged-in user. (and potentially, your entire team).

Issue #1790920 by alexpott, japicoder, LinL, heyrocker: Move cron_last(), node_cron_last() and common_test_cron() to state system.

This reverts commit 405c5fbd.

Issue #1691438 follow-up by Devin Carlson: Remove 8.x update function for {file_managed()}.filename should NOT be binary (and case-sensitive by default), which was added in 7.x.

Issue #1798724 by andreiashu, Albert Volkman, alexpott: Convert drupal_js_cache_files() to State system.

Revert "Issue #1798732 by Dean Reilly, westie, alexpott, sun: convert install_task() variable to use state system."

This reverts commit d3edf501.

This caused unexpected errors with installation on sites with existing
settigs.php files. Rolling back until keyvalue store is available during
installation.