Fix for ResourceNotFound issue on 7.5 installation

* Fixed Path to dojo.js in Site.Master
* Fixed Path to loading.gif in Index.aspx
* Fixed ResourceNotFound for

/cms/Shell/1.0.456/ClientResources/dtk/dijit/themes/tundra/images/smallArrowDown.png
in style.less

https://github.com/Geta/CacheManager/issues/5