* Create a repository app for documents, first step
* Step two (broken)
* Complete the implementation of document repository and add invoices
* Add support for invoices
* Update submodules
* Add a boolean to define item as part of a set
* Add contextual help in admin
* Introduce support to sets and to item code lookup
Also review the url path for pagination
* Replace ckeditor with tinymce due to deprecation
* Remove any ckeditor dependency from old migrations
Disable alters, replace create with plain models.TextField
* Reformat files
* Add more hardening in image_upload
* Cleanup and maintenance
* Net-to-serial broadcast messages to all clients
This will make all clients to stay in sync with any operation
occurring, like when having multiple JMRI instances
* Update README and python version in containers
