ITS ID prefix registry

Hi all,

I'm getting an error now on unit tests that use the XLIFF 2.0 ID prefix registry file
(https://tools.oasis-open.org/version-control/browse/wsvn/xliff/trunk/xliff2-fragid/registry.txt)

The new entry for ITS uses 3 spaces as the separation between the URI and the prefix.
The example use a TAB, and I believe that is what we agreed upon when defining the format (See
https://lists.oasis-open.org/archives/xliff/201405/msg00014.html) 

This bring up the point that it would be good to have the format described somewhere.
I propose to add the description to the https://wiki.oasis-open.org/xliff/FragIDPrefixRegistration wiki page (I can do that).

Also, one small note: "# Life entries" should be "# Live entries"


Cheers,
-yves