WIP: update repo to code mirror v4
WIP: it sort of works again

history still broken
and it prints the previous line after eval
Fixes styling and up and down buttons
More fixes
And this too :neckbeard:
Everything seems to work now except for

printing an error
Whoohoo! It works!
updates default editor to CM4
Some cleanup and a last couple of fixes.
clean up of protest
Merge pull request #185 from albertjan/repl-codemirror-v4

REPL with codemirror v4