[ENH]Added a few extra themes for Plugin Slider (jquery plugin Anything slider). Didn't add the whole master zip from the git repo through composer since there was lots of fat (images) and they would have meant license issues in addition. Therefore, I added only the css and lgpl'd theme images at the vendors_extra folder. Ref: https://github.com/CSS-Tricks/AnythingSlider-Themes

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@49306 b456876b-0849-0410-b77d-98878d47e9d5