* kB instead of KB
When kilobyte is referred to 1000 bytes the abbreviation should be written with lower case "k" as kB. Upper case K is usually intended to refer to 1024 multiplier
See this page: https://en.wikipedia.org/wiki/Kilobyte
* Updated php.net link for some MemCache properties [skip ci]
* Changed protocol to https for links to php.net in comments
* Changed protocol to https for links to php.net in code
* Changed www.php.net (http) to secure.php.net (https) in comments
* Changed www.php.net (http) to secure.php.net (https) in code
* Changed protocol to https for links to php.net in UPGRADE.md
* Changed protocol to https for links to pecl.php.net in comments
* Changed us.php.net to secure.php.net (https) in comments
* Changed protocol to https for links to php.net in docs
* Changed www.php.net (http) to secure.php.net (https) in docs
* Changed protocol to https for links to pecl.php.net in docs
* Changed ru/jp.php.net to secure.php.net (https) in docs
Don't sure about russian guide: is this links meant to be for guide on russian, or not?
* When uses filter \yii\filters\PageCache, then yii\web\JsonResponseFormatter sets Response::$content as null, howerer \yii\filter\PageCache has been restore content
Property `RetryAcquireTrait::$retryDelay` sets the minimum delay, but not the exact delay. In fact, the delay may be longer. Because of this, sometimes less than 20 blocking attempts occur. Checking the exact number of locks sometimes leads to the following errors:
```
$ vendor/bin/phpunit --filter=testRetryAcquire
PHPUnit 4.8.34 by Sebastian Bergmann and contributors.
F
You should really fix these slow tests (>500ms)...
1. 1050ms to run yiiunit\framework\mutex\RetryAcquireTraitTest:testRetryAcquire
Time: 4.08 seconds, Memory: 44.00MB
There was 1 failure:
1) yiiunit\framework\mutex\RetryAcquireTraitTest::testRetryAcquire
Failed asserting that 19 is identical to 20.
/yii2/tests/framework/mutex/RetryAcquireTraitTest.php:36
/yii2/vendor/phpunit/phpunit/phpunit:52
FAILURES!
Tests: 1, Assertions: 3, Failures: 1.
```
I reworked the test so that it checks the duration of the delays, but not the exact number of blocking attempts.
PHPUnit must get the data that will be passed to the tests, before executing them. That's why you can't prevent the dataProvider to be executed using `$this->markTestSkipped()` inside a test. Instead, you must use a skipping inside data provider when the test cannot be executed.
Now Oracle tests are skipped without fails when Oracle isn't installed:
```
$ vendor/bin/phpunit --filter=BuildLikeCondition --group=oci --verbose
...
There was 1 skipped test:
1) yiiunit\framework\db\oci\QueryBuilderTest::testBuildLikeCondition
Test for yiiunit\framework\db\oci\QueryBuilderTest::testBuildLikeCondition skipped by data provider
Could not execute Connection::quoteValue() method: Connection::dsn cannot be empty.
```