remove kernel selector from header

- add kernel name to indicator
- float kernel logo where indicator used to be
add text placeholder for kernels with no logo

capital first initial on gray field
Another widget promise bug fix
add an humanize function that prettify shortcut on macos
Add notion of actions to celltoolbar

modify toolbar.js to be able to deal with actions.

modify maintoolbar to deal with the new action architecture

add a way to triger notification widget hiding
fix john coments
Fix comments

move humanize-map out of function call to have only one instance
complete unicode mac symbol
adresses Min comments x2
Fix persistence API,
it expecited a view dictionary not a dictionary of view promises
Make the pager look better
invoke css
Add shadow to pager handle
invoke css
fix rebase after kill of layout manager
note to self
make pseudo action in their own dcit.

make test more reliable by adding data-attributes to buttons.
Thinner handle, single handlebar
invoke css
various fixes in utils.js

revealed by linters

- remove duplicate WrappedError definition
- regex_split doesn't actually allow string separator
- remove various unused variables
- fix some incorrect regex escaping
- add missing quotes in $('body')
- remove a `for(attr in object)` because javascript