add page-up and page-down functionality to the autocomplete dropdown
Validate slider value, when limits change
The value of slider changes in frontend, and readout, but not in python obj.
Sending data back to python object after slider values change
A comma after `this.touch`
test: changing text of cell resets rendered status
Partial updates of css and visible + simplification of widget_container
changing the text should reset rendered flag
widget simplification continued
widget changes continued
correction
Introduce info/warning/danger to notification area

Add corresponding style.

Should fix #5984

Error when (auto)saving and things along should stand out in the
UI for the user to investigate the reason as soon as possible not to
loose work later.
Allow switching kernel from the notebook UI
Change displayed kernel name when our session is started
Style kernel name
Line dropdown up on RHS of kernel name
Store kernelspec in notebook metadata on change
Start kernel according to loaded notebook metadata
Add method to change codemirror mode of all code cells
Set codemirror mode from kernelspecs