Django-tables2

- Feature: Added an `ExportMixin` to export table data in various export formats (CSV, XLS, etc.) using [tablib](http://docs.python-tablib.org/en/latest/).
- Defer expanding `Meta.sequence` to `Table.__init__`, to make sequence work in combination with `extra_columns` (fixes [450](https://github.com/bradleyayers/django-tables2/issues/450))
- Fixed a crash when `MultiTableMixin.get_tables()` returned an empty array ([454](https://github.com/bradleyayers/django-tables2/pull/455) by [pypetey](https://github.com/pypetey)

- Call before_render when rendering with the render_table template tag (fixes [447](https://github.com/bradleyayers/django-tables2/issues/447))

- Make `title()` lazy ([443](https://github.com/bradleyayers/django-tables2/pull/443) by [ygwain](https://github.com/ygwain), fixes [#438](https://github.com/bradleyayers/django-tables2/issues/438))
- Fix `__all__` by populating them with the names of the items to export instead of the items themselves.
- Allow adding extra columns to an instance using the `extra_columns` argument. Fixes [403](https://github.com/bradleyayers/django-tables2/issues/403), [#70](https://github.com/bradleyayers/django-tables2/issues/70)
- Added a hook `before_render` to allow last-minute changes to the table before rendering.
- Added `BoundColumns.show()` and `BoundColumns.hide()` to show/hide columns on an instance of a `Table`.
- Use `<listlike>.verbose_name`/`.verbose_name_plural` if it exists to name the items in the list. (fixes [166](https://github.com/bradleyayers/django-tables2/issues/166))

- Add missing pagination to the responsive bootstrap template ([440](https://github.com/bradleyayers/django-tables2/pull/440) by [tobiasmcnulty](https://github.com/tobiasmcnulty))

- Add new template `bootstrap-responsive.html` to generate a responsive bootstrap table. (Fixes [436](https://github.com/bradleyayers/django-tables2/issues/436))

_Full disclosure: as of april 1st, 2017, I am an employee of [Zostera](http://zostera.nl/), as such I will continue to maintain and improve django-tables2._

- Made `TableBase.as_values()` an iterator ([432](https://github.com/bradleyayers/django-tables2/pull/432) by [pziarsolo](https://github.com/pziarsolo))
- Added `JSONColumn` for data in JSON format.
- Added `__all__` in `django_tables2/__init__.py` and `django_tables2/columns/__init__.py`
- Added a setting `DJANGO_TABLES2_TEMPLATE` to allow project-wide overriding of the template used to render tables (fixes [434](https://github.com/bradleyayers/django-tables2/issues/434)).