User management dialog

[Alexander-Krause-Glau]

Provide user management GUI forms with respect to ExplorViz-Archive/explorviz-backend#27

[Alexander-Krause-Glau]

@dan0x09 Today, I tried to implement an endpoint for the authentication service that essentially returns a container with a list of all string-based roles (atm a role is simply a string). This endpoint should be used for the ember-power-select based role selection.

I instantly disliked this implementation and deleted all this code when I reached the frontend. Due to the (mostly) RESTful design this container classes come really unhandy when using Ember-Data. Ideally, we should only need to call this.get('store').findAll('role') and insert the obtained roles in the ember-power-select dialog.

Eventualy, this means that I will try to refactor the backend's roles for authorization (classes instead of strings)

[czirkelbach]

TODO

• list of all users
• remove single user
• edit user information (name, password, role)

[dan0x09]

Done with 00c355e, 2760f06, 197acd2, 8a43f28, 022a055, 09ae116, ac19c65 (last).