Ensure that "change" event is fired only once per "setValue" call

[aik099]

Current results:

• setValue for input/file: change fires 0 times
• setValue for textarea: change fires 0 times

Since selectOption, check and uncheck for Sahi does fire change event without us doing manual firing, then I guess it's some bug in SahiClient side.

Tests added in Behat/Mink#495

[aik099]

There is output from running latest test suite, that is relevant to this issue:

11) Behat\Mink\Tests\Driver\Js\ChangeEventTest::testSetValueChangeEvent with data set "input default" ('the-input-default', 'from empty', 'from existing')
initial value setting triggers change event
Failed asserting that 0 matches expected '1'.

.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:150
.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:48

12) Behat\Mink\Tests\Driver\Js\ChangeEventTest::testSetValueChangeEvent with data set "input text" ('the-input-text', 'from empty', 'from existing')
initial value setting triggers change event
Failed asserting that 0 matches expected '1'.

.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:150
.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:48

13) Behat\Mink\Tests\Driver\Js\ChangeEventTest::testSetValueChangeEvent with data set "input email" ('the-email', 'from empty', 'from existing')
initial value setting triggers change event
Failed asserting that 0 matches expected '1'.

.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:150
.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:48

14) Behat\Mink\Tests\Driver\Js\ChangeEventTest::testSetValueChangeEvent with data set "textarea" ('the-textarea', 'from empty', 'from existing')
initial value setting triggers change event
Failed asserting that 0 matches expected '1'.

.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:150
.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:48

15) Behat\Mink\Tests\Driver\Js\ChangeEventTest::testSetValueChangeEvent with data set "file" ('the-file', 'from empty', 'from existing')
initial value setting triggers change event
Failed asserting that 0 matches expected '1'.

.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:150
.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:48

16) Behat\Mink\Tests\Driver\Js\ChangeEventTest::testSetValueChangeEvent with data set "select" ('the-select', '30')
initial value setting triggers change event
Failed asserting that 0 matches expected '1'.

.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:150
.../vendor/behat/mink/driver-testsuite/tests/Js/ChangeEventTest.php:48