Added jinja2 template backend.

import sys

from django.conf import settings

from django.template import TemplateDoesNotExist

from django.utils import six

from django.utils.module_loading import import_string

from jinja2 import (

    DebugUndefined, FileSystemLoader, TemplateNotFound, Undefined)

from .base import BaseEngine

from .utils import csrf_input_lazy, csrf_token_lazy

class Jinja2(BaseEngine):

    app_dirname = 'jinja2'

    def __init__(self, params):

        params = params.copy()

        options = params.pop('OPTIONS').copy()

        super(Jinja2, self).__init__(params)

        environment = options.pop('environment', 'jinja2.Environment')

        environment_cls = import_string(environment)

        options.setdefault('autoescape', True)

        options.setdefault('loader', FileSystemLoader(self.template_dirs))

        options.setdefault('auto_reload', settings.DEBUG)

        options.setdefault('undefined',

                           DebugUndefined if settings.DEBUG else Undefined)

        self.env = environment_cls(**options)

    def from_string(self, template_code):

        return Template(self.env.from_string(template_code))

    def get_template(self, template_name):

        try:

            return Template(self.env.get_template(template_name))

        except TemplateNotFound as exc:

            six.reraise(TemplateDoesNotExist, TemplateDoesNotExist(exc.args),

                        sys.exc_info()[2])

class Template(object):

    def __init__(self, template):

        self.template = template

    def render(self, context=None, request=None):

        if context is None:

            context = {}

        if request is not None:

            context['request'] = request

            context['csrf_input'] = csrf_input_lazy(request)

            context['csrf_token'] = csrf_token_lazy(request)

        return self.template.render(**context)