Demos: active state font color overrides, view source collapsibles font, minor corrections.
Demos: applied new demos styling to slider tooltip extentsion demo page. Moved CSS and JS source files to same folder so the demo won't break when we move it to a subfolder.
Demos: arrow icons for view source collapsibles because they look better than the plus and minus icons on SD screen.

Signed-off-by: Jasper de Groot <mail@ugomobi.com>
Demos: Popup widget page - replaced intro text, adjusted tooltip example style, set max-height for lightbox images.
Demos: source view - the textarea that appears when you double click the source code shouldn't be resizable.
Demos: getting the demo section in shape.