Move undo and redo in "core:"

src/app/editor.coffee

@@ -108,8 +108,8 @@ class Editor extends View
       'core:select-all': @selectAll
       'core:backspace': @backspace
       'core:delete': @delete
-      'undo': @undo
-      'redo': @redo
+      'core:undo': @undo
+      'core:redo': @redo
       'cut': @cutSelection
       'copy': @copySelection
       'paste': @paste

src/app/keymaps/atom.coffee

@@ -13,6 +13,8 @@ window.keymap.bindKeys 'body'
   'backspace': 'core:backspace'
   'shift-backspace': 'core:backspace'
   'delete': 'core:delete'
+  'meta-z': 'core:undo'
+  'meta-Z': 'core:redo'
   pageup: 'core:page-up'
   pagedown: 'core:page-down'
   'meta-S': 'save-all'

src/app/keymaps/editor.coffee

@@ -7,8 +7,6 @@ window.keymap.bindKeys '.editor',
   'meta-x': 'cut'
   'meta-c': 'copy'
   'meta-v': 'paste'
-  'meta-z': 'undo'
-  'meta-Z': 'redo'
   'alt-meta-w': 'toggle-soft-wrap'
   'ctrl-[': 'fold-current-row'
   'ctrl-]': 'unfold-current-row'