Improvement on Assets

- Assets is remove, and replace by AssetStack
- AssetStack is the same as Assets except for
   - add method 'processAssets', a replacement of 'getAssetLocations' and much more, see 'processor' section
   - add method 'prepareAssetsFor', a method wrapper for 'assetsFor', 'excludeByName' and 'processAssets'
   - add method 'filterByDOMPosition' to filter assets by his DOM or Default DOM
- Processor System to process Assets before usage (locations, ... and aggregation, compression later)

Asset learn to really clone itself
AssetType learn his position and order for DOM rendering

JSP and Tymeleaf usages of Assets move to AssetsStack