Revert "Add Project::observeBuffers"

This reverts commit b6fe72ef9e.

Conflicts:
	src/project.coffee

spec/project-spec.coffee

@@ -479,7 +479,7 @@ describe "Project", ->
         runs ->
           expect(results).toHaveLength 0
 
-  describe ".observeBuffers(callback)", ->
+  describe ".eachBuffer(callback)", ->
     beforeEach ->
       atom.project.bufferForPathSync('a')
 
@@ -490,7 +490,7 @@ describe "Project", ->
       callback = (buffer) ->
         callbackBuffer = buffer
         count++
-      atom.project.observeBuffers(callback)
+      atom.project.eachBuffer(callback)
       expect(count).toBe 1
       expect(callbackBuffer).toBe atom.project.getBuffers()[0]
 
@@ -501,7 +501,7 @@ describe "Project", ->
         callbackBuffer = buffer
         count++
 
-      atom.project.observeBuffers(callback)
+      atom.project.eachBuffer(callback)
       count = 0
       callbackBuffer = null
       atom.project.bufferForPathSync(require.resolve('./fixtures/sample.txt'))

src/git.coffee

@@ -98,7 +98,7 @@ class Git
         @refreshStatus()
 
     if @project?
-      @subscribe @project.observeBuffers (buffer) => @subscribeToBuffer(buffer)
+      @subscribe @project.eachBuffer (buffer) => @subscribeToBuffer(buffer)
 
   ###
   Section: Event Subscription

src/project.coffee

@@ -54,15 +54,6 @@ class Project extends Model
   onDidChangePath: (callback) ->
     @emitter.on 'did-change-path', callback
 
-  # Extended: Immediately invoke the given callback for all existing buffers.
-  # Then invoke the given callback when a new buffer has been created. For
-  # example, when {::open} is called, this is fired.
-  #
-  # * `callback` {Function}
-  #   * `buffer` {TextBuffer} the new buffer
-  observeBuffers: (callback) ->
-    callback(buffer) for buffer in @getBuffers()
-    @onDidCreateBuffer(callback)
 
   # Extended: Invoke the given callback when a new buffer has been created. For
   # example, when {::open} is called, this is fired.
@@ -363,12 +354,11 @@ class Project extends Model
     subscriber = args.shift() if args.length > 1
     callback = args.shift()
 
-    message = 'Use Project::observeBuffers instead'
-    message += '; Project::observeBuffers no longer accepts a subscriber parameter. Call `subscriber.subscribe(atom.project.observeBuffers(cb))`' if subscriber?
-
-    disposable = @observeBuffers(callback)
-    subscriber.subscribe(disposable) if subscriber?
-    disposable
+    callback(buffer) for buffer in @getBuffers()
+    if subscriber
+      subscriber.subscribe this, 'buffer-created', (buffer) -> callback(buffer)
+    else
+      @on 'buffer-created', (buffer) -> callback(buffer)
 
   # Deprecated: delegate
   registerOpener: (opener) ->