Updated classes to use the DevMode Dandelion class instead of Datatables' one
Used Dandelion utilities and cleaned code
Refactored the WebResourceGenerator using the extension mechanism
 * Added new features for Export, Appear, ExtraConf, ExtraFile and ExtraHtml
 * Added a new scope for the download.js dependency
Cleaned code and comments
Improved Javascript generation (useless instancitions, indentations)