Set jinja options from a config file in a template

[ghost]

As mentioned in my comment in #135, I've worked on a patch that allows jinja environment options to be specified in a config file in a cookiecutter template.

I put these options in a separate config file, so that older versions of cookiecutter don't ask for this as an option. I think this is going to break a lot of old versions of cookiecutter anyway if the cookiecutter templates start using these options :( I guess this requires some thought...

[coveralls]

Coverage increased (+0.15%) when pulling 9f6ca0d on luked:jinja_options_in_config_file into 3b84343 on audreyr:master.

[hackebrot]

Hey! 👋

I'm closing this in favor of 6cc1831 of #848.

Thank you for your contribution!