Render same markdown hint for issue, merge request, wiki and comment forms

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/stylesheets/framework/markdown_area.scss

@@ -106,6 +106,7 @@
 }
 
 .markdown-area {
+  @include border-radius(0);
   background: #FFF;
   border: 1px solid #ddd;
   min-height: 140px;

app/assets/stylesheets/pages/note_form.scss

@@ -56,6 +56,10 @@
   .note_text {
     width: 100%;
   }
+
+  .comment-hints {
+    margin-top: -12px;
+  }
 }
 
 /* loading indicator */
@@ -168,7 +172,7 @@
   color: #999;
   background: #FFF;
   padding: 7px;
-  margin-top: -11px;
+  margin-top: -7px;
   border: 1px solid $border-color;
   font-size: 13px;
 }

app/views/projects/wikis/_form.html.haml

@@ -23,9 +23,7 @@
     .col-sm-10
       = render layout: 'projects/md_preview', locals: { preview_class: "md-preview" } do
         = render 'projects/zen', f: f, attr: :content, classes: 'description form-control js-quick-submit'
-        .col-sm-12.hint
-          .pull-left Wiki content is parsed with #{link_to "GitLab Flavored Markdown", help_page_path("markdown", "markdown"), target: '_blank'}
-          .pull-right Attach files by dragging & dropping or #{link_to "selecting them", '#', class: 'markdown-selector' }.
+        = render 'projects/notes/hints'
 
       .clearfix
       .error-alert

app/views/shared/issuable/_form.html.haml

@@ -27,14 +27,7 @@
     = render layout: 'projects/md_preview', locals: { preview_class: "md-preview", referenced_users: true } do
       = render 'projects/zen', f: f, attr: :description,
                                classes: 'description form-control js-quick-submit'
-      .col-sm-12.hint
-        .pull-left
-          Parsed with
-          #{link_to 'GitLab Flavored Markdown', help_page_path('markdown', 'markdown'), target: '_blank'}.
-        .pull-right
-          Attach files by dragging & dropping
-          or #{link_to 'selecting them', '#', class: 'markdown-selector' }.
-
+      = render 'projects/notes/hints'
       .clearfix
       .error-alert
   %hr