feat(message-ui/edit-info): add information about message editor

This comes in the form of the user's avatar, along with a hover
title that shows username and edit time. As a side note, this
requires us to start saving 'editBy' id as part of message updates.

This has been tested with all 4 of the current avatar methods.

fixes #824

client/methods/updateMessage.coffee

@@ -23,6 +23,7 @@ Meteor.methods
 
 		Tracker.nonreactive ->
 
+			message.editBy = Meteor.userId()
 			message.ets = new Date(Date.now() + TimeSync.serverOffset())
 			message = RocketChat.callbacks.run 'beforeSaveMessage', message
 

client/views/app/message.coffee

+wasEdited = (msg) ->
+	msg.ets and msg.t not in ['s', 'p', 'f', 'r', 'au', 'ru', 'ul', 'nu', 'wm', 'uj', 'rm']
 Template.message.helpers
 	actions: ->
 		return RocketChat.MessageAction.getButtons(this)
@@ -46,8 +48,13 @@ Template.message.helpers
 
 	system: ->
 		return 'system' if this.t in ['s', 'p', 'f', 'r', 'au', 'ru', 'ul', 'nu', 'wm', 'uj', 'rm']
-	edited: ->
-		return @ets and @t not in ['s', 'p', 'f', 'r', 'au', 'ru', 'ul', 'nu', 'wm', 'uj', 'rm']
+	edited: -> wasEdited(@)
+	editTime: ->
+		return "" unless wasEdited(@)
+		moment(@ets).format('LL hh:mma') #TODO profile pref for 12hr/24hr clock?
+	editedBy: ->
+		return "" unless wasEdited(@)
+		Meteor.users.findOne(@editBy ? Meteor.userId())?.username
 	pinned: ->
 		return this.pinned
 	canEdit: ->

client/views/app/message.html

@@ -5,7 +5,17 @@
 		<span class="info">
 			<span class="time">{{time}}</span>
 		{{#if edited}}
-			<span class="edited">({{_ "edited"}})</span>
+			<span class="edited">
+				(<a
+					title='{{_ "edited"}} at {{editTime}} {{_ "by"}} {{editedBy}}'
+					class="thumb thumb-small user-card-message"
+					href="#"
+					data-username="{{editedBy}}"
+					tabindex="1">
+						{{> avatar username=editedBy}}
+				</a>
+				{{_ "edited"}})
+			</span>
 		{{/if}}
 		{{#if private}}
 			<span class="private">{{_ "Only_you_can_see_this_message"}}</span>

packages/rocketchat-theme/assets/stylesheets/base.less

@@ -2448,6 +2448,13 @@ a.github-fork {
 		display: block;
 		width: 40px;
 		height: 40px;
+		&.thumb-small {
+			position: initial;
+			width: 20px;
+			height: 20px;
+			display: inline-block;
+			vertical-align: bottom;
+		}
 	}
 	.info {
 		font-size: 12px;

server/methods/updateMessage.coffee

@@ -29,6 +29,8 @@ Meteor.methods
 			RocketChat.models.Messages.cloneAndSaveAsHistoryById originalMessage._id
 
 		message.ets = new Date()
+		# save who message was edited by
+		message.editBy = Meteor.userId()
 
 		if urls = message.msg.match /([A-Za-z]{3,9}):\/\/([-;:&=\+\$,\w]+@{1})?([-A-Za-z0-9\.]+)+:?(\d+)?((\/[-\+=!:~%\/\.@\,\w]+)?\??([-\+=&!:;%@\/\.\,\w]+)?#?([\w]+)?)?/g
 			message.urls = urls.map (url) -> url: url