Added silent option to loadLanguages (#2147)

This adds an option to `loadLanguages` which prevents all warning messages.

components/index.js

@@ -30,7 +30,9 @@ function loadLanguages(languages) {
 
 	getLoader(components, languages, loaded).load(lang => {
 		if (!(lang in components.languages)) {
-			console.warn('Language does not exist: ' + lang);
+			if (!loadLanguages.silent) {
+				console.warn('Language does not exist: ' + lang);
+			}
 			return;
 		}
 
@@ -46,4 +48,9 @@ function loadLanguages(languages) {
 	});
 }
 
+/**
+ * Set this to `true` to prevent all warning messages `loadLanguages` logs.
+ */
+loadLanguages.silent = false;
+
 module.exports = loadLanguages;

index.html

@@ -226,6 +226,8 @@ <h2>Usage with Node</h2>
 
 	<p><strong>Note</strong>: Do <em>not</em> use <code class="language-javascript">loadLanguages()</code> with Webpack or another bundler, as this will cause Webpack to include all languages and plugins. Use the babel plugin described above.</p>
 
+	<p><strong>Note</strong>: <code class="language-javascript">loadLanguages()</code> will ignore unknown languages and log warning messages to the console. You can prevent the warnings by setting <code class="language-javascript">loadLanguages.silent = true</code>.</p>
+
 </section>
 
 <section class="language-markup">