ENH: Add jinja support

[westurner]

[westurner]

• [ ] DOC: README.rst: -O jinja:template=path/to/template.jinja,+autoescape
  • autoescape=True is the default
  • This does not add a trailing newline for you.
    • The jinja template (e.g. .jinja, .jinja2, .j2) must end with a trailing newline to prevent everything being concatenated to the same line.

[westurner]

• [ ] build context from result_objs:List
• [ ] print_template_variables(context)
• [ ] fsloader(template_path).template.render(context)