Python-wekan

This patch release fixes two bugs on Sandstorm:

* Drag and drop was broken;
* Avatars weren’t working.

This release features:

* Trello boards importation, including card history, assigned members, labels,
comments, and attachments;
* Invite new users to a board using an email address;
* Autocompletion in the minicard editor. Start with <kbd></kbd> to start a
board member autocompletion, or <kbd></kbd> for a label;
* Improve the user interface on small screens so that Wekan could be used on the
mobile web;
* Accelerate the initial page rendering by sending the data on the initial HTTP
response instead of waiting for the DDP connection to open;
* Support images attachments copy pasting;
* On Sandstorm, expose the Wekan grain title and URL to the Sandstorm shell;
* Support Wekan deployment under a sub-path of a domain name.

New languages supported: Arabic, Catalan, Italian, and Russian.

Thanks to GitHub users AlexanderS, fisle, floatinghotpot, FuzzyWuzzie, mnutt,
ndarilek, SirCmpwn, and xavierpriour for their contributions.

This release is a large re-write of the previous code base. This release marks
the beginning of our new user interface and continues to improve the overall
performance and security. It also features the following improvements:

* A new user account system, including the possibility to reset a forgotten
password, to change the password, or to enable email confirmation (all of
which were previously impossible);
* Avatar customization, including the possibility to upload images and to choose
one from Gravatar or the user initials (on Sandstorm we use the avatar exposed
by Sandstorm);
* Cards multi-selection to facilitate batch actions such as moving all the cards
of selection, or attaching a label or a member to them;
* Automatic drafts saving synced with the server;
* Keyboard navigation, press `?` to read the list of available shortcuts;
* The possibility to restore archived boards, lists, and cards.

Starting from this release we will also distribute official docker images on
both the [GitHub release page](https://github.com/wekan/wekan/releases) and on
the [DockerHub](https://hub.docker.com/r/mquandalle/wekan). We also configured
Heroku one-click install and improved Sandstorm integration with the integration
of its build-in sharing model.

New languages supported: Chinese, Finnish, Spanish, Korean, and Russian.

Special thanks to GitHub users ePirat, nata-goddanti, ocdtrekkie, and others who
have supportive during this *traversée du desert*, and to neynah for the Wekan
icons.

This release continues the implementation of basic features of a “kanban”
software, especially:

* Basic card attachments. If the attached file is an image we generate and
display a thumbnail that can be used as a card “cover” (visible in the board
general view);
* User names mentions and auto-completion in card description and comments
(though we don’t have any notification system for now, making this feature a
less useful that it should);
* Filter views, current filtering options are based on labels and assigned
members;
* Labels creation and suppression at the board level (previously we had a fixed
list of labels);
* Customization of the board background color.

This release is also the first one to introduce localization of the user
interface.

New languages supported: French, German, Japanese, Portuguese, and Turkish.

This release fixes the following bugs:

* Unexpected lost of the card sorting on the server side;
* Fix a bug during board creation;
* Focus the new list form if the board is empty.

This release starts the transition from a toy project to something useful. Along
with some security and performance improvements (for instance, opening a card
used to take a long time because it was re-generated the entire DOM whereas only
the popover was new). New features includes:

* Add and remove labels to cards;
* Assign and unassign members to cards;
* Archive cards (though restoration is not yet possible);
* Board stars;
* Markdown and emoji support in comments and card description;
* Emoji auto-completion in the text editor;
* Some keyboard shortcuts (eg `Ctrl`+`Enter` to submit a multi-line input).

We also introduced basic support for the [Sandstorm](https://sandstorm.io)
platform, and distribute a `spk` (Sandstorm PacKage) for this release and
subsequent.