Handling of hidden files except .saikuaccess

some changes to open handling of hidden files/folders
these changes are to open the use of the acl repository to third party extensions.

1) added param 'all' (boolean default false) to GET /saiku/{username}/repository2
    if true the service returns also hidden files (except .saikuaccess files)
2) changed bolocking control of point starting filename on GET, POST, DELETE /saiku/{username}/repository2/resource. now only .saikuaccess files are blocked.
3) changed bolocking control of point starting filename on GET, POST /saiku/{username}/repository2/resource/acl. now only .saikuaccess files are blocked.
4) in failing GET acl the SaikuServiceException is wrapped by a WebApplicationException to return correct 403 status