move JShrink Minifier to vendor/

include/functions.php

@@ -2386,7 +2386,6 @@
 	}
 
 	function get_minified_js($files) {
-		require_once 'lib/jshrink/Minifier.php';
 
 		$rv = '';
 

index.php

@@ -113,8 +113,6 @@
 		'use strict';
 		require({cache:{}});
 	<?php
-		require_once 'lib/jshrink/Minifier.php';
-
 		print get_minified_js(["tt-rss.js",
 			"functions.js", "feedlist.js", "viewfeed.js", "PluginHost.js"]);
 	?>

prefs.php

@@ -80,8 +80,6 @@
 		'use strict';
 		require({cache:{}});
 	<?php
-		require_once 'lib/jshrink/Minifier.php';
-
 		print get_minified_js(["functions.js", "prefs.js"]);
 	?>
 	</script>