Cmsplugin-contact-plus

- Drop Django 1.4 support
- Replace https://github.com/centralniak/django-inline-ordering dependency with https://github.com/iambrandontaylor/django-admin-sortable.

**Upgrading**: Remove `'inline_ordering'` from `INSTALLED_APPS`and add `'adminsortable'` instead. To ensure the compatibility of the new dependency with your project's Django version, have a look at the "Supported Django Versions", "Installation", and "Configuration" sections of the [README](https://github.com/iambrandontaylor/django-admin-sortable/blob/master/README.md).

- Fix `MANIFEST.in`. Locale files are now correctly included

- Add a missing migration

- Renamed plugin field `submit` to `submit_button_text` to achieve django CMS 3.3/3.4 compatibility. Please migrate your database and update your templates.

- Adding Spanish translation
- Support migrations for django **1.7** and django cms **3.0.6**