Minor, visual improvements

[cfedermann]

Several minor improvements to the project should be implemented.

In no particular order:

• update page templates with more descriptive text (<-- depends on input from Thierry);
• make results table sortable by column (using either Bootstrap or jQuery);
• render one to five stars instead of raw polarity integer scores (<-- Bootstrap should have an image for that);
• remove any output of raw XML results from the rendering of the results;
• integrate link to the XSD schema into the page template;
• integrate link to the sample .zip archive into the page template (<-- depends on input from Thierry);

[cfedermann]

All tasks NOT requiring input from Thierry should be done by now...