Enable editing for inline threads.

Currently there's a bug where editing more than once without reloading the page
causes it to successively get more and more broken.

lms/static/coffee/src/discussion/views/discussion_thread_view_inline.coffee

@@ -6,6 +6,9 @@ if Backbone?
       "click .expand-post": "expandPost"
       "click .collapse-post": "collapsePost"
 
+    initialize: ->
+      super()
+
     initLocal: ->
       @$local = @$el.children(".discussion-article").children(".local")
       if not @$local.length
@@ -25,7 +28,7 @@ if Backbone?
       @delegateEvents()
       @renderShowView()
       @renderAttrs()
-      #@renderTags()  #TODO: Decide if we want tags on inline threads
+      @renderTags()  #TODO: Decide if we want to show tags on inline threads
       @$("span.timeago").timeago()
       @$el.find('.post-extended-content').hide()
       if @expanded
@@ -50,7 +53,6 @@ if Backbone?
           @trigger "thread:responses:rendered"
           @$('.loading').remove()
 
-    edit: ->
 
     toggleClosed: (event) ->
       #TODO: showview
@@ -85,7 +87,7 @@ if Backbone?
       abbreviated = DiscussionUtil.abbreviateString @model.get('body'), 140
       @model.set('abbreviatedBody', abbreviated)
 
-    expandPost: (event) ->
+    expandPost: (event) =>
       @expanded = true
       @$el.addClass('expanded')
       @$el.find('.post-body').html(@model.get('body'))
@@ -105,3 +107,7 @@ if Backbone?
       @$el.find('.collapse-post').css('display', 'none')
       @$el.find('.post-extended-content').hide()
       @$el.find('.expand-post').css('display', 'block')
+
+    createEditView: () ->
+      super()
+      @editView.bind "thread:update", @expandPost

lms/static/sass/_discussion.scss

@@ -2214,8 +2214,77 @@ body.discussion {
   .wmd-spacer3 {
     left: 300px;
   }
+  .edit-post-form {
+    width: 100%;
+    margin-bottom: 20px;
+    @include clearfix;
+    @include box-sizing(border-box);
+
+    .form-row {
+      margin-top: 20px;
+    }
+
+    .post-cancel {
+      @include white-button;
+      float: left;
+      margin: 10px 0 0 15px;
+    }
+
+    .post-update {
+      @include blue-button;
+      float: left;
+      height: 37px;
+      margin-top: 10px;
+      padding-bottom: 2px;
+
+      &:hover {
+        border-color: #222;
+      }
+    }
+
+    .edit-post-title, .edit-post-tags {
+      width: 100%;
+      height: 40px;
+      padding: 0 10px;
+      box-sizing: border-box;
+      border-radius: 3px;
+      border: 1px solid #aaa;
+      font-size: 16px;
+      font-family: $sans-serif;
+      color: #333;
+      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.15) inset;
+    }
+
+    .tagsinput {
+      padding: 10px;
+      @include box-sizing(border-box);
+      border: 1px solid #aaa;
+      border-radius: 3px;
+      background: #fff;
+      font-family: 'Monaco', monospace;
+      font-size: 13px;
+      line-height: 1.6;
+      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3) inset;
+
+      span.tag {
+        margin-bottom: 0;
+      }
+    }
+  }
+  .thread-tags {
+    margin-top: 20px;
+  }
+
+  .thread-tag {
+    padding: 3px 10px 6px;
+    border-radius: 3px;
+    color: #333;
+    background: #c5eeff;
+    border: 1px solid #90c4d7;
+    font-size: 13px;
+  }
 }
 
 .discussion-user-threads {
   @extend .discussion-module
-}
+}