Update config schema to use some new features.
Fix :memo:
Fix spec
Fix renaming error throwing exception in checkout-head-revision command
Merge branch 'master' into ns-workspace-custom-elements
Properly emit item argument in pane:before-item-destroyed legacy event
Add TextEditorElement and make TextEditorView a wrapper around it

This is the next step on converting all internal views to custom
elements instead of using SpacePen. The TextEditorElement instances
are associated with ::__spacePenView fields that are used for supporting
legacy access paths via atom.workspaceView.
Destroy model if TextEditorView is explicitly removed for compatibility