Remove view registry references from the workspace model layer

Removed various ::getView methods from the model. Using the atom.views
global in the views for now, but going to switch them over to using a
locally assigned view registry instead in a subsequent commit.
Change ::setModel to ::initialize on all element classes
Simplify ViewRegistry::addViewProvider API

It now takes two arguments, a model constructor and a create view
callback that is passed the model.

Signed-off-by: Max Brunsfeld <maxbrunsfeld@gmail.com>
Start bundling language-clojure

It is now MIT licensed which was the reason it was removed as a
bundled package originally.
x out flaky spec
Merge pull request #4365 from atom/ns-view-registry-cleanup

Clean up view registry API
Add update menus on Windows
Add unsupported state to update manager
:arrow_up: atom-shell@0.19.3
:arrow_up: atom-shell@0.19.4
Merge pull request #4246 from atom/ks-add-update-menus-on-windows

Add update menus on windows
:arrow_up: grunt-atom-shell-installer@0.11
:lipstick:
Remove waitsForAnimationFrame spec helper

It doesn’t work reliably on CI.
Null guard workspace element for deprecated update-available dispatch
Un-f
Spawn new atom.exe immediately on quitAndInstall
Test TextEditorElement::setUpdatedSynchronously without waiting

Another attempt to fix flakiness.
Log from quitAndInstall
Add specs for PaneContainer::onDidAddPane