Add Angelscript language (#3844)

* Add AngelScript scriping language

* Add AngelScript sample

* Initial implementation of Angelscript

* Update Angelscript tm_scope and ace_mode

* Move Angelscript after ANTLR

* Updated grammar list

* Alphabetical sorting for Angelscript

* Angelscript grammar license is unlicense

* Add ActionScript samples

* Added a heuristic for .as files

* Whitelist sublime-angelscript license hash

* Added heuristic test for Angelscript and Actionscript

* Remove .acs from Angelscript file extensions

samples/ActionScript/HelloWorld.as

@@ -0,0 +1,13 @@
+package mypackage
+{
+	public class Hello
+	{
+		/* Let's say hello!
+		 * This is just a test script for Linguist's Actionscript detection.
+		 */
+		public function sayHello():void
+		{
+			trace("Hello, world");
+		}
+	}
+}