Upload restlets that use RestletFileUpload fails on 5.2 after Seam 2.x migration

Seam 2 introduce a MultiPart filter that is automatically stacked in Seam internal filter chain.
This filter eats all the binary data and make them available in the MultipartRequest Seam class.

Because of that filter, any call to Apache FileUpload, or RestletFileUpload will return a null file.

Solution is to include a new Helper class in ui-web that will provide an encapsulation :

• 5.2 version will use the implementation based on Seam MultipartRequest
• 5.1 version will use the implementation based on Apache FileUpload

Commited in a branch because I need branch NXP-1085 to be merged before.