Changes the twig loader in the MessageRenderer class.
Changes the twig loader in the MessageRenderer class.

This commit changes the twig loader from an \Twig_Loader_Array to a \Twig_Loader_Chain.

There are new helper methods to add new loaders.
Avtonom/EmailTemplateBundle,gnat42/LexikMailerBundle,lexik/LexikMailerBundle,Avtonom/EmailTemplateBundle,bendavies/LexikMailerBundle,lexik/LexikMailerBundle,gnat42/LexikMailerBundle,bendavies/LexikMailerBundle