Add a MessageManager to atom.messages

spec/message-manager-spec.coffee

@@ -7,6 +7,10 @@ fdescribe "MessageManager", ->
   beforeEach ->
     manager = new MessageManager
 
+  describe "the atom global", ->
+    it "has a messages instance", ->
+      expect(atom.messages instanceof MessageManager).toBe true
+
   describe "adding events", ->
     addSpy = null
 

src/atom.coffee

@@ -146,6 +146,9 @@ class Atom extends Model
   # Public: A {TooltipManager} instance
   tooltips: null
 
+  # Experimental: A {MessageManager} instance
+  messages: null
+
   # Public: A {Project} instance
   project: null
 
@@ -220,6 +223,7 @@ class Atom extends Model
     ViewRegistry = require './view-registry'
     CommandRegistry = require './command-registry'
     TooltipManager = require './tooltip-manager'
+    MessageManager = require './message-manager'
     PackageManager = require './package-manager'
     Clipboard = require './clipboard'
     GrammarRegistry = require './grammar-registry'
@@ -246,6 +250,7 @@ class Atom extends Model
     @keymaps = new KeymapManager({configDirPath, resourcePath})
     @keymap = @keymaps # Deprecated
     @tooltips = new TooltipManager
+    @messages = new MessageManager
     @commands = new CommandRegistry
     @views = new ViewRegistry
     @packages = new PackageManager({devMode, configDirPath, resourcePath, safeMode})