[Misc] Apply xar:format after XCOMMONS-2180 (Make sure that all XAR XML files are using XML 1.1 when using the xar:format mojo)

* fix dependencies

[Misc] The standard is to call the top level IT test : AllITs (plural). And not "AllIT". Also removed config overwrite which are not needed since the default is AllITs.
+ Added explanation as to why we need the failsafe plugin in the pom.xml files
+ Fixed missing test which wasn't executed at all: DeletedAttachmentsIT

  * Fix since annotation for only stable branch

  * Ensure to build an URI when #getURI is called for backward
    compatibility
  * Change the since annotations

  * Fix the problem by encoding the attachment part in the URI and by
    decoding it in VFS when getting the attachment.
  * Fix the VfsResourceReferenceResolver to not rely anymore on an URI
    since it will break again because of the space on the attachment.

  * Provide a better solution, with a new design for
    VfsResourceReference: now we are not forced to rely anymore on URI
in the resource.

  * Provide a fix by using URLEncoder/Decoder before creating the URI,
    this is enough to fix the original issue, but we need more
investigation in case of usage of an attachment with spaces

* add missing Unstable annotations

* add a helper in the script service