Define externally accessible contants with 'var' instead of 'const'

Just as we did with classes, define other constants that are (or
may be) used from other modules with 'var' to cut down on warnings.

https://bugzilla.gnome.org/show_bug.cgi?id=785084

js/ui/components/autorunManager.js

@@ -15,7 +15,7 @@ const SETTING_START_APP = 'autorun-x-content-start-app';
 const SETTING_IGNORE = 'autorun-x-content-ignore';
 const SETTING_OPEN_FOLDER = 'autorun-x-content-open-folder';
 
-const AutorunSetting = {
+var AutorunSetting = {
     RUN: 0,
     IGNORE: 1,
     FILES: 2,
@@ -378,4 +378,4 @@ var AutorunNotification = new Lang.Class({
     }
 });
 
-const Component = AutorunManager;
+var Component = AutorunManager;