* add migration and basic UI for changing a user's theme
* update user themem
* use right text on button
* load theme based on users' selection
* load theme based on users' selection in pwa too
* update sample config
* delete older theme loading
* implement AfterLoad to set users' theme properly
* set up default theme when creating a user. This uses the installation wide theme
* use flash messages for error
* set default theme when creating a user from the cli
* fix @lunny review
* refactor setting router code
splitted up one huge router settings file into the smaller files
representing the actual page structure
* move code to subfolder
* rename functions
* renamed files
* add copyright information
