Avoid conflicts when composer is wrapped in older sf versions, fixes #1835

src/Composer/IO/ConsoleIO.php

@@ -79,7 +79,7 @@ class ConsoleIO implements IOInterface
      */
     public function isVeryVerbose()
     {
-        return $this->output->getVerbosity() >= OutputInterface::VERBOSITY_VERY_VERBOSE;
+        return $this->output->getVerbosity() >= 3; // OutputInterface::VERSOBITY_VERY_VERBOSE
     }
 
     /**
@@ -87,7 +87,7 @@ class ConsoleIO implements IOInterface
      */
     public function isDebug()
     {
-        return $this->output->getVerbosity() >= OutputInterface::VERBOSITY_DEBUG;
+        return $this->output->getVerbosity() >= 4; // OutputInterface::VERBOSITY_DEBUG
     }
 
     /**