OO-422: new layout for the administration tree, break the "system infromations" tabbed panel in single controllers under a main menu point, add a new system informations controller with some VIP values

OO-422: first step of the rearrangement of the administration site, breaks the system informations in multiple menu points, rewrite some controllers in a more modern way

NEW default theme for OpenOLAT
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- remove old "default"
- minor markup changes in velocity templates
- minor markup changes in JavaClasses (add css-classes to components)
- new iconset
- update yaml
- new theme:  "openolat"
- theme.readme
- ignore sass-cache