Add Symfony ClassLoader (needed for bootstrap)

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "vendor/yaml"]
 	path = vendor/yaml
 	url = https://github.com/fabpot/yaml.git
+[submodule "vendor/symfony/Symfony/Component/ClassLoader"]
+	path = vendor/symfony/Symfony/Component/ClassLoader
+	url = https://github.com/symfony/ClassLoader.git

vendor/symfony/Symfony/Component/ClassLoader

@@ -0,0 +1 @@
+Subproject commit 0e6ee8d07dda6920106048247d41249201604e76