Merge commit 'be90f19'

Conflicts:
	DependencyInjection/Configuration.php
	Generator/CaptchaGenerator.php
	composer.json

DependencyInjection/Configuration.php

@@ -41,6 +41,7 @@ class Configuration implements ConfigurationInterface
                 ->scalarNode('distortion')->defaultValue(true)->end()
                 ->scalarNode('max_front_lines')->defaultValue(null)->end()
                 ->scalarNode('max_behind_lines')->defaultValue(null)->end()
+                ->arrayNode('backgroundColor')->prototype('scalar')->end()
             ->end()
         ;