Fix small issues

libs/Console/ClearCache.php

@@ -19,5 +19,7 @@ class ClearCache extends SymfonyCommand
         $output->writeln("Clearing cache at '" . Cache::getDirectory() ."'");
         Cache::clear();
         $output->writeln("<info>Cache cleared</info>");
+
+        return 0;
     }
 }

libs/Console/Generate.php

@@ -54,6 +54,8 @@ class Generate extends DauxCommand
 
         // Generate the documentation
         $daux->getGenerator()->generateAll($input, $output, $width);
+
+        return 0;
     }
 
     protected function prepareProcessor(Daux $daux, InputInterface $input, OutputInterface $output, $width)

libs/Console/Serve.php

@@ -49,5 +49,7 @@ class Serve extends DauxCommand
         echo "Daux development server started on http://{$host}:{$port}/\n";
 
         passthru("{$binary} -S {$host}:{$port} {$base}/index.php");
+
+        return 0;
     }
 }

libs/ContentTypes/Markdown/LinkRenderer.php

@@ -22,6 +22,7 @@ class LinkRenderer implements InlineRendererInterface, ConfigurationAwareInterfa
     public function __construct($daux)
     {
         $this->daux = $daux;
+        $this->parent = new \League\CommonMark\Inline\Renderer\LinkRenderer();
     }
 
     /**
@@ -69,7 +70,6 @@ class LinkRenderer implements InlineRendererInterface, ConfigurationAwareInterfa
     protected function isExternalUrl($url)
     {
         return preg_match('#^(?:[a-z]+:)?//|^mailto:#', $url);
-        $this->parent = new \League\CommonMark\Inline\Renderer\LinkRenderer();
     }
 
     /**

libs/Server/ExtensionMimeTypeGuesser.php

@@ -29,5 +29,7 @@ class ExtensionMimeTypeGuesser implements MimeTypeGuesserInterface
         if ($extension == "js") {
             return "application/javascript";
         }
+
+        return null;
     }
 }