Smoothed out loading of SVG FIP images and cleaned up top-level theme SCSS files

* Delayed display of SVG FIP images to avoid white box flicker.
* Removed jQuery Mobile CSS imports from non-JavaScript SCSS files. Only needed in regular theme SCSS files.
* Removed mobile view CSS and changed prefix to oldie for theme-ns-ie.scss in each of the themes.
* Changed prefix to oldie for theme-ns-ie.scss in the CLF 2.0 theme.
* Fixed no JS and pe-disable scenarios for loading of SVG FIP images.
* Fixed a minor comment in pe-ap.js