Add css include

A big beluga.css is generated from all css contained in /beluga/module/MODULE_NAME/view/css during the compilation.

Css.getHtmlInclude and Javascript.getHtmlInclude are tools function to generate html string that can directly be added to a html file.
Correct css folder creation
Remove useless comment, add usefull comment.
Merge pull request #237 from brissa-a/AddCssInclude

Add css include