introduce class ui-my-icon to avoid conflicts

Builds on the changes in 5f5635cc397220001b231c75190204f6b541d8c2
Update tab styles for jQuery UI 1.10
Add environment option backend-development

* Sets consolidate_resources to “never” to override resource consolidation in admin
* “never” is a new option that always overrides the given option, even if explicit and uses “false”
Update buttons in admin menu, dialogs to jQUI 1.10
Update jQuery to 1.11.0 and jQuery UI to 1.10.4