Handles 1.39 deprecations, simplifies skin registration

In 1.36 the skin registration process was modified to support
registration for common skin meta data

This removes warnings in >= 1.39.

Pivot.skin.php

@@ -9,8 +9,6 @@
  
 
 class SkinPivot extends SkinTemplate {
-	public $skinname = 'pivot', $stylename = 'pivot', $template = 'pivotTemplate', $useHeadElement = true;
-	
 	public function getDefaultModules() {
 		global $wgPivotFeatures;
 		$wgPivotFeaturesDefaults = array(
@@ -37,29 +35,16 @@ class SkinPivot extends SkinTemplate {
 		if ( $wgPivotFeatures['preloadFontAwesome'] ) {
 			$this->getOutput()->addHeadItem('font', '<link rel="preload" href="'.$wgLocalStylePath.'/pivot/assets/fonts/fontawesome-webfont.woff2?v=4.7.0" as="font" type="font/woff2" crossorigin="anonymous" />');
 		}
-		
-		$this->getOutput()->addModuleStyles('skins.pivot.styles');
 		return parent::getDefaultModules();
 	}
-	
-	public function initPage(OutputPage $out) {
-		global $wgLocalStylePath;
-		parent::initPage($out);
-
-		$viewport_meta = 'width=device-width, user-scalable=yes, initial-scale=1.0';
-		$out->addMeta('viewport', $viewport_meta);
-		$out->addModules('skins.pivot.js');
-	}
-
 }
 
 
-class pivotTemplate extends BaseTemplate {
+class PivotTemplate extends BaseTemplate {
 	public function execute() {
 		global $wgUser;
 		global $wgPivotFeatures;
 		Wikimedia\suppressWarnings();
-		$this->html('headelement');
 		switch ($wgPivotFeatures['usePivotTabs']) {
 			case true:
 			    ob_start();
@@ -278,14 +263,9 @@ class pivotTemplate extends BaseTemplate {
 			<a class="exit-off-canvas"></a>	
 		</div>
 
-		
-		<?php $this->printTrail(); ?>
-
 			<?php if ($this->data['isarticle'] && $wgPivotFeatures['addThisPUBID'] !== '') { ?>
 				<script type="text/javascript" src="//s7.addthis.com/js/300/addthis_widget.js#pubid=<?php echo $wgPivotFeatures['addThisPUBID']; ?>" async="async"></script>
 			<?php } ?>	
-		</body>
-		</html>
 
 <?php
 		Wikimedia\restoreWarnings();

skin.json

@@ -10,10 +10,26 @@
 	"descriptionmsg": "pivot-desc",
 	"type": "skin",
 	"ValidSkinNames": {
-		"pivot": "Pivot"
+		"pivot": {
+			"class": "SkinPivot",
+			"args": [
+				{
+					"name": "pivot",
+					"template": "PivotTemplate",
+					"bodyOnly": true,
+					"responsive": true,
+					"scripts": [
+						"skins.pivot.js"
+					],
+					"styles": [
+						"skins.pivot.styles"
+					]
+				}
+			]
+		}
 	},
 	"requires": {
-		"MediaWiki": ">= 1.35.0"
+		"MediaWiki": ">= 1.39.0"
 	},
 	"MessagesDirs": {
 		"Skinpivot": [