Don't render empty console banners

This change will allow modules to provide the console banner
information dynamically and returning an empty string when nothing
should be rendered. 

A module can now check the environment and capabilities before returning
the information.

This was missing in the last commit

library/Zend/Mvc/View/Console/RouteNotFoundStrategy.php

@@ -221,8 +221,14 @@ protected function getConsoleBanner(ConsoleAdapter $console, ModuleManagerInterf
                     continue; // this module does not provide a banner
                 }
 
+                // Don't render empty completely empty lines
+                $banner = $module->getConsoleBanner($console);
+                if ($banner == '') {
+                    continue;
+                }
+
                 // We colorize each banners in blue for visual emphasis
-                $banners[] = $console->colorize($module->getConsoleBanner($console), ColorInterface::BLUE);
+                $banners[] = $console->colorize($banner, ColorInterface::BLUE);
             }
         }