Cmsplugin-blocks

--------------------------

* Moved zip file validation to ``utils.validate_zip`` method;
* Use sorl thumbnail in default Album template;
* Added basic image file validation from mass upload, close 4;
* Added mass upload file size limit, close 3;
* Added translation catalog for french language;
* Added some CSS in template for Album inline admin form;
* Better README.

--------------------------

* Better plugin form for Album and Card.

--------------------------

* Adjusted 'blank' and 'max_length' field attribute for every models
(migrations have been rebooted again).

--------------------------

* Remove long text 'brief' and 'content' field from Album and AlbumItem,
replace with a simple 'title' field;
* Added 'order' field to AlbumItem to be able to order ressources list;
* Added mass upload field to AlbumForm;
* Renamed every 'background' fields to 'image' for better naming consistency.

--------------------------

* Added Album plugin.

--------------------------

Reboot:

* Better Makefile;
* Added dev requirements;
* Updated 'setup.py' requirements;
* Removed establishment opening plugin (too much specific for now);
* Reset initial migrations (totally backward incompatible);
* Moved Banner to Hero;
* Moved Diptych to Card;
* Added template field to every plugin.