Use atom.commands

Also, use atom.keymaps directly rather than using
the jQuery.fn.enableKeymap spec helper
Don't use WorkspaceView
Use atom-space-pen-views
Use Workspace::addOpener
Use Cursor::onDidChangePosition
Remove calls to deprecated cursor/selection methods
Use Point::traverse
Use TextEditor::lineTextForBufferRow
Restore default ::insert arguments
Require CompositeDisposable through 'atom'
Store settings using atom.config, not GrammarRegistry

Still need to remove calls to these two private APIs:

* ::addProperties
* ::settingsForScopeDescriptor
Update select list to work with atom-space-pen-views SelectList
Merge pull request #86 from atom/mb-modernize

Remove uses of deprecated APIs