[Xesam] Meaning of xesam:url

[Michael Albinus]

Hi,

I'm currently playing with different search engine. It looks to me like
all of them have an own idea of xesam:url, which makes it a little bit
hard to interpret in a client.

- The XesamOntology95 says as data type "list of URLs". This seems to be
  an error, all engines return just a string.

- When it is a local file, beagle returns a "file:///a/b" URL. Contrary,
  strigi returns a local file name like "/a/b". I guess, it shall always
  be a URL.

- The engines use xesam:url for providing further information. Examples:

  * "file:///.../Mail/Local Folders/Inbox/?id=240915" means file "Inbox",
    char position 240915 (beagle)

  * "/home/albinus/Mail/default/21/ChangeLog" means (email in) file
    "21", attachment "ChangeLog" (strigi)

  * ".../gnome-keyring_2.20.orig.tar.gz/gnome-keyring-2.20/po/ChangeLog"
    means a file in a zipped tar (strigi)

  I believe, such information shall be given in other xesam fields.

Best regards, Michael.