user creation and removal

[rlebre]

Added section in Configuration page about creation and removal of users. However, this pull request only takes into account the dev branch in bioinformatics-ua/dicoogle as it considers the refactored user web services.

Solves #11

[Enet4]

this pull request only takes into account the dev branch in bioinformatics-ua/dicoogle as it considers the refactored user web services.

Can you double-check whether there were any changes in this services? As far as I can recall, this should still work in v2.

[rlebre]

@Enet4 in fact, I think v2.5.0 only supports the HTTP method PUT to create a user. Changes have been made to change the API from PUT to POST and change also the DELETE method. The pull request referring that is bioinformatics-ua/dicoogle#380

Regarding the white spaces commented above, they were added by markdown-formatter plugin for VSCode. Although there was not complain by an editor, I can revert upon your confirmation about this matter.

[Enet4]

Right, now I remember that change. You can document it as PUT in the main corpus and append an "unreleased" block to document the next version.

<div class="note unreleased" >
<h5>Breaking change in Dicoogle 3</h5>
<p>Starting from Dicoogle 3.0.0, creating new users should be done with the `POST` method instead of `PUT`.</p>
</div>

[rlebre]

Also fixed the wrong method to delete users.
Moreover, I added the information of the persistence of the users in users.xml to the note unreleased, as the fixes are applied only in v3.0.0 by bioinformatics-ua/dicoogle#380

[Enet4]

Let's bring in pending changes and work on fresh new content for the learning pack!