update codemirror again to pick up some recent fixes

RaymondLim · RaymondLim · commit d4207fa69843 · 2014-04-23T12:13:42.000-07:00
diff --git a/src/thirdparty/CodeMirror2 b/src/thirdparty/CodeMirror2
@@ -1 +1 @@
-Subproject commit eed9a2c8c782711fc25c0002d643f016f20061ef
+Subproject commit 0558dfe76ceae8764011c982d13a766087c9dd20
