closing feature #5156
It is now possible to share a file from a form.
Furthermore, shareable characteristic has been centralized into SimpleDocument
For security reasons, elements of sharing are checked before creation.

Conflicts:
	war-core/src/main/java/com/silverpeas/sharing/servlets/FileSharingRequestRouter.java
	war-core/src/main/webapp/attachment/jsp/displayAttachedFiles.jsp
closing feature #5518
- adjust resource bundle (global and specific message)
- clean unused code
- fixing error