Remove WorkspaceView references from spell-check-spec.coffee
Use event subscription methods instead of ::on + strings
Use Disposables instead of Subscriber mixin
Don’t make SpellCheckView a subclass of View

It’s not really a view anymore. Should probably be renamed.
Call .dispose() on deactivate instead of .off()
Fix context menu format
Use TextEditor::moveToEndOfLine
Use setGrammar instead of messing with overrides