Fix normalization in init command with --no-interaction and --require

When calling `composer init --no-interaction --require foo/bar:dev-master` it
would fail because in non-interactive mode it would only split on space.

src/Composer/Command/InitCommand.php

@@ -259,7 +259,7 @@ EOT
 
         if ($requires) {
             foreach ($requires as $key => $requirement) {
-                $requires[$key] = preg_replace('{^([^=: ]+)[=: ](.*)$}', '$1 $2', $requirement);
+                $requires[$key] = $this->normalizeRequirement($requirement);
                 if (false === strpos($requires[$key], ' ') && $input->isInteractive()) {
                     $question = $dialog->getQuestion('Please provide a version constraint for the '.$requirement.' requirement');
                     if ($constraint = $dialog->ask($output, $question)) {
@@ -328,6 +328,7 @@ EOT
     {
         $requires = array();
         foreach ($requirements as $requirement) {
+            $requirement = $this->normalizeRequirement($requirement);
             list($packageName, $packageVersion) = explode(" ", $requirement, 2);
 
             $requires[$packageName] = $packageVersion;
@@ -336,6 +337,11 @@ EOT
         return empty($requires) ? new \stdClass : $requires;
     }
 
+    protected function normalizeRequirement($requirement)
+    {
+        return preg_replace('{^([^=: ]+)[=: ](.*)$}', '$1 $2', $requirement);
+    }
+
     protected function getGitConfig()
     {
         if (null !== $this->gitConfig) {