Add creation icons for document cabinet, metadata, comments and tags links.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/document_comments/icons.py

@@ -3,3 +3,4 @@ from __future__ import absolute_import, unicode_literals
 from appearance.classes import Icon
 
 icon_comments_for_document = Icon(driver_name='fontawesome', symbol='comment')
+icon_comment_add = Icon(driver_name='fontawesome', symbol='plus')

mayan/apps/document_comments/links.py

@@ -4,15 +4,16 @@ from django.utils.translation import ugettext_lazy as _
 
 from navigation import Link
 
-from .icons import icon_comments_for_document
+from .icons import icon_comment_add, icon_comments_for_document
 from .permissions import (
     permission_comment_create, permission_comment_delete,
     permission_comment_view
 )
 
 link_comment_add = Link(
-    args='object.pk', permissions=(permission_comment_create,),
-    text=_('Add comment'), view='comments:comment_add',
+    args='object.pk', icon_class=icon_comment_add,
+    permissions=(permission_comment_create,), text=_('Add comment'),
+    view='comments:comment_add',
 )
 link_comment_delete = Link(
     args='object.pk', permissions=(permission_comment_delete,),