[xliff] Specification - 1.1 draft 2

Hi Everyone,

I've attached the working draft 2 of the specification.
All marked changes are based on XLIFF 1.0 specification (not 1.1 draft 1).
- Red is the deleted text.
- Green is the inserted text.
- Yellow indicates a note (will be deleted in final specification).

I have not put the changes proposed by Matt for coord and font (they were
included in his <reformat> proposal) as we haven't discussed it at all I
think.
The attributes for <tools> are also not finalized as I'm still uncertain
what we do about the names (see the note).

-yves