Created CSS class for beta sticker.
Marked MathJax and Image2 plugins as beta features.
Added ckeditor-sample-isbeta meta to existing samples.
Right aligned new and beta. Adjusted border of beta.
Removed new from several samples that are not new any more.
Removed ckeditor-sample-isnew meta from several samples.
Changed title for sourcedialog sample.
Moved the sourcedialog sample to plugins section in samples index.
Synchronize Mathjax plugin name in sample index and sample meta.
Merge branch 'index-refac' into major