Emoji's by themselves appear 3x as large. (#3072)

* Added the ability to create larger emojis by editing sprites.css.
Changed renderMessageBody.js so that if a user's message contained only an emoji, it appears 3x as large.

* Fixed spacing and equality issues.

* Update renderMessageBody.js

Cosmetic fixes

packages/rocketchat-emojione/sprites.css

@@ -16,6 +16,24 @@
   overflow: hidden;
 }
 
+.big_emojione {
+  image-rendering: optimizeQuality;
+  font-size: inherit;
+  height: 66px;
+  width: 66px;
+  position: relative;
+  display: inline-block;
+  margin: 0 .15em;
+  line-height: normal;
+  vertical-align: middle;
+  background-image: url("../../packages/emojione_emojione/assets/sprites/emojione.sprites.png");
+  background-size: 4100% 4000%;
+  background-repeat: no-repeat;
+  text-indent: 100%;
+  white-space: nowrap;
+  overflow: hidden;
+}
+
 .emojione-0023-20e3 {
   background-position: 2.5% 0%; }
 

packages/rocketchat-ui-message/message/renderMessageBody.js

@@ -22,5 +22,46 @@ renderMessageBody = function(msg) {
 
 	msg.html = message.html.replace(/\n/gm, '<br/>');
 
+	if (singleEmojiCheck(msg)) {
+		msg.html = (msg.html).replace('emojione ', 'big_emojione ');
+	}
+
 	return msg.html;
 };
+
+/**
+ *Checks to see if a message contains only an emoji span
+ *@para {msg} some html message
+ *@return {false} the html message either doesn't 
+ *contain an emoji span, or contains other characters
+ */
+singleEmojiCheck = function(msg) {
+	var str = msg.html;
+	str = str.trim();
+
+	//checks to make sure it's a span
+	if (!str.includes('<') || !str.includes('>')) {
+		return false;
+	}
+
+	if (str.charAt(0) !== '<' || str.charAt(str.length - 1) !== '>') {
+		return false;
+	}
+
+	if (str.indexOf('>') === str.lastIndexOf('>')) {
+		return false;
+	}
+
+	//checks to make sure it's the only span
+	str = str.substring(str.indexOf('<') + 1, str.lastIndexOf('>') - 1);
+	if (!str.includes('<') || !str.includes('>')) {
+		return false;
+	}
+
+	if (str.indexOf('<') < str.lastIndexOf('>')) {
+		return false;
+	}
+
+	return true;
+};
+