Remove usage of drupal_strtolower()

I had to do a reroll and i haven't found the function, only the declaration in file core/includes/unicode.inc. Maybe this can be removed.

+++ b/core/modules/block_content/src/Tests/BlockContentCreationTest.php
@@ -165,7 +165,7 @@ public function testBlockDelete() {
+      'id' => Unicode::strlower($edit['info[0][value]']),

Must be str*TO*lower

Typo solved, thanks penyaskito

We need to consider the disruption of this patch and we might need to update #2350615: [policy, no patch] What changes can be accepted during the Drupal 8 beta phase? wrt to removing already deprecated functions.

Needs a reroll

git ac https://www.drupal.org/files/issues/2361823-11.patch
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 60396  100 60396    0     0  49985      0  0:00:01  0:00:01 --:--:-- 50881
error: patch failed: core/modules/search/search.module:244
error: core/modules/search/search.module: patch does not apply

This issue is a prioritized change (deprecate function removal) as per #2350615: [policy, no patch] What changes can be accepted during the Drupal 8 beta phase? and it's benefits outweigh any disruption. Committed 80eccb1 and pushed to 8.0.x. Thanks!

M  core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php
M  core/modules/color/color.module
M  core/modules/entity_reference/src/EntityReferenceController.php
M  core/modules/search/search.module
M  core/modules/update/update.report.inc

Whilst on size this patch appears disruptive - the majority of changes are to tests. Above is a list of the non test parts of the patch. That's out of 52 files changing.