temporarily removed the PopOver and replaced it with a dialog, until
errors with the PopOver-Control are resolved.
Removed obsolete tests.
Added edit-button and wired the button to the challengeView.
Added some Documentation
Disabled the challengeSolvingUI if no challenge is selected (at startup)
removed obsolete stuff
asdf
asdf (reverted from commit 1d4b7d3eba2196bfcae6d32138adce2bcf5dfd9e)
removed obsolete stuff (reverted from commit 32c7922927025191fa3bb7c0b325b73ab059be96)
Finished the editing-mode