Fixed lowercase supposed class names (#1544)

This PR fixes a bug with supposed class names.

Lowercase supposed class names are no longer highlighted.

**Before**:
![before](https://user-images.githubusercontent.com/20878432/44656379-e7c17900-a9f8-11e8-8b1a-7f1dd694263e.png)

**After**:
![after](https://user-images.github
usercontent.com/20878432/44656379-e7c17900-a9f8-11e8-8b1a-7f1dd694263e.png)

Author: RunDevelopment

components/prism-javascript.js

@@ -1,7 +1,10 @@
 Prism.languages.javascript = Prism.languages.extend('clike', {
 	'class-name': [
 		Prism.languages.clike['class-name'],
-		/[_$A-Z\xA0-\uFFFF][$\w\xA0-\uFFFF]*(?=\.(?:prototype|constructor))/
+		{
+			pattern: /(^|[^$\w\xA0-\uFFFF])[_$A-Z\xA0-\uFFFF][$\w\xA0-\uFFFF]*(?=\.(?:prototype|constructor))/,
+			lookbehind: true
+		}
 	],
 	'keyword': [
 		{

components/prism-javascript.min.js

@@ -727,7 +727,10 @@ Prism.languages.clike = {
 Prism.languages.javascript = Prism.languages.extend('clike', {
 	'class-name': [
 		Prism.languages.clike['class-name'],
-		/[_$A-Z\xA0-\uFFFF][$\w\xA0-\uFFFF]*(?=\.(?:prototype|constructor))/
+		{
+			pattern: /(^|[^$\w\xA0-\uFFFF])[_$A-Z\xA0-\uFFFF][$\w\xA0-\uFFFF]*(?=\.(?:prototype|constructor))/,
+			lookbehind: true
+		}
 	],
 	'keyword': [
 		{

prism.js

@@ -1,5 +1,6 @@
 Foo.prototype.bar;
 Bar.constructor;
+fooBar.prototype.bar;
 
 ----------------------------------------------------
 
@@ -14,6 +15,13 @@ Bar.constructor;
 	["class-name", "Bar"],
 	["punctuation", "."],
 	"constructor",
+	["punctuation", ";"],
+
+	"\nfooBar",
+	["punctuation", "."],
+	"prototype",
+	["punctuation", "."],
+	"bar",
 	["punctuation", ";"]
 ]