[Intl][Form] Update tests, TimeZoneTransformer, and DateTimeToLocalizedStringTransformer for the GMT and UTC split in ICU

The [GMT timezone has been split from the UTC](http://site.icu-project.org/download/59) timezone [in CLDR](http://cldr.unicode.org/index/downloads/cldr-31) (which ICU is based on).

For example, the code blow:
* before ICU 59.1 would return "GMT" in all cases
* with ICU 59.1 it returns "UTC" for the first three ('z', 'zz', 'zzz')
  and "Coordinated Universal Time" for the last two ('zzzz', 'zzzzz').

```php
foreach (['z', 'zz', 'zzz', 'zzzz', 'zzzzz'] as $pattern) {
    $formatter = new \IntlDateFormatter('en', IntlDateFormatter::MEDIUM, IntlDateFormatter::SHORT, new \DateTimeZone('UTC'), IntlDateFormatter::GREGORIAN, $pattern);
    var_dump($formatter->format(new \DateTime('@0')));
}
```

Similarly Form's `DateTimeToLocalizedStringTransformer` is also affected:

```php
$transformer = new DateTimeToLocalizedStringTransformer('UTC', 'UTC', null, \IntlDateFormatter::FULL);
var_dump($transformer->transform(new \DateTime('2010-02-03 04:05:06 UTC')));
// ICU 58.2: '03.02.2010, 04:05:06 GMT'
// ICU 59.1: '03.02.2010, 04:05:06 Koordinierte Weltzeit'
```

Refer to added and modified test cases for more changes. I split this PR in two commits for easier review. First commit updates ICU data (generated files), the second updates code and test cases to be compatible with updated data.

Author: jakzal

Tests/Extension/Core/DataTransformer/DateTimeToLocalizedStringTransformerTest.php

@@ -61,11 +61,13 @@ public function dataProvider()
             array(\IntlDateFormatter::FULL, \IntlDateFormatter::NONE, null, 'Mittwoch, 3. Februar 2010', '2010-02-03 00:00:00 UTC'),
             array(null, \IntlDateFormatter::SHORT, null, '03.02.2010, 04:05', '2010-02-03 04:05:00 UTC'),
             array(null, \IntlDateFormatter::MEDIUM, null, '03.02.2010, 04:05:06', '2010-02-03 04:05:06 UTC'),
-            array(null, \IntlDateFormatter::LONG, null, '03.02.2010, 04:05:06 GMT', '2010-02-03 04:05:06 UTC'),
+            array(null, \IntlDateFormatter::LONG, null, '03.02.2010, 04:05:06 UTC', '2010-02-03 04:05:06 UTC'),
+            array(null, \IntlDateFormatter::LONG, null, '03.02.2010, 04:05:06 UTC', '2010-02-03 04:05:06 GMT'),
             // see below for extra test case for time format FULL
             array(\IntlDateFormatter::NONE, \IntlDateFormatter::SHORT, null, '04:05', '1970-01-01 04:05:00 UTC'),
             array(\IntlDateFormatter::NONE, \IntlDateFormatter::MEDIUM, null, '04:05:06', '1970-01-01 04:05:06 UTC'),
-            array(\IntlDateFormatter::NONE, \IntlDateFormatter::LONG, null, '04:05:06 GMT', '1970-01-01 04:05:06 UTC'),
+            array(\IntlDateFormatter::NONE, \IntlDateFormatter::LONG, null, '04:05:06 UTC', '1970-01-01 04:05:06 GMT'),
+            array(\IntlDateFormatter::NONE, \IntlDateFormatter::LONG, null, '04:05:06 UTC', '1970-01-01 04:05:06 UTC'),
             array(null, null, 'yyyy-MM-dd HH:mm:00', '2010-02-03 04:05:00', '2010-02-03 04:05:00 UTC'),
             array(null, null, 'yyyy-MM-dd HH:mm', '2010-02-03 04:05', '2010-02-03 04:05:00 UTC'),
             array(null, null, 'yyyy-MM-dd HH', '2010-02-03 04', '2010-02-03 04:00:00 UTC'),
@@ -85,6 +87,9 @@ public function dataProvider()
      */
     public function testTransform($dateFormat, $timeFormat, $pattern, $output, $input)
     {
+        IntlTestHelper::requireFullIntl($this, '59.1');
+        \Locale::setDefault('de_AT');
+
         $transformer = new DateTimeToLocalizedStringTransformer(
             'UTC',
             'UTC',
@@ -101,9 +106,12 @@ public function testTransform($dateFormat, $timeFormat, $pattern, $output, $inpu
 
     public function testTransformFullTime()
     {
+        IntlTestHelper::requireFullIntl($this, '59.1');
+        \Locale::setDefault('de_AT');
+
         $transformer = new DateTimeToLocalizedStringTransformer('UTC', 'UTC', null, \IntlDateFormatter::FULL);
 
-        $this->assertEquals('03.02.2010, 04:05:06 GMT', $transformer->transform($this->dateTime));
+        $this->assertEquals('03.02.2010, 04:05:06 Koordinierte Weltzeit', $transformer->transform($this->dateTime));
     }
 
     public function testTransformToDifferentLocale()