- issue #150 - opening the add user to group dialog now loads all members (and changes the paging to load all)

- changed simple ace editor editor onChange debounce to throttle

Squashed commits:
[a4270eb] - added example for exit code test syntax
- dashboard live view can now be toggled (live/not live)
- server msg is now polled  every 2.5 min
- chaning pagination size  now resets the page to 1 (because the current page might be invalid after page size changed)

  - instead added syntax highlighting
- changed options from string to number
- added compare files test to test content docs

- backend & test stuff is not published/tested yet

  - this overwrites the editor settings font size and is no persistent
  - when the editor settings are changed then the quick zoom is reset

- added #comment for blackbox tests and regex tests
- removed two not used packages

- the settings useReplaceWhiteSpacesWithBullets & useDiffIfOutputMismatched are now taken globally from the do exercises site

- todo: remove old imports

- test content can now be empty (for syntax tests)
- changed test syntax guide
- fixed i18n

- fixed test syntax guide for blackbox regular lines
- fixed typo

- added do exercise site submit tests panel

- normal do exercises could not be solved because editor was read only
- added key to group exercises site (react key)