Update cookiecutter vars in sphinx files.

Many variables were missing the `cookiecutter` prefix.

In conf.py:
Added prefix to `project_name` and `description`.
Changed `ChangeMyName` to `cookiecutter.author_name`.
Changed `ChangeToMyName` to `cookiecutter.author_name`.

In Makefile and make.bat:
Added prefix to `project_name`.

In LICENSE.rst:
Changed `full_name` to `author_name` and added prefix.