Update ACE Editor to version 1.2.9

The new ACE editor introduces full support for emojis (and, thereby, UTF-16 characters with high- and low-surrogates). Hence, we can remove our custom fix.

Further, this update will allow emojis to be used in pair programming sessions.

vendor/assets/javascripts/ace/snippets/csound_document.js

@@ -0,0 +1,17 @@
+define("ace/snippets/csound_document",["require","exports","module"], function(require, exports, module) {
+"use strict";
+
+exports.snippetText = "# <CsoundSynthesizer>\n\
+snippet synth\n\
+	<CsoundSynthesizer>\n\
+	<CsInstruments>\n\
+	${1}\n\
+	</CsInstruments>\n\
+	<CsScore>\n\
+	e\n\
+	</CsScore>\n\
+	</CsoundSynthesizer>\n\
+";
+exports.scope = "csound_document";
+
+});