Changes from -03 to -05
Added below table 1 in note (1) that "RSVP encryption with ESP
and RSVP authentication with AH work over non-RSVP nodes
in 'Tunnel Mode with Address Preservation'"
Clarified in section 6.3 that IPsec AH also secures the
immutable fields of the outer header (comment from Bob
Briscoe)
Simplified in section 2 the comment that trust in group keying
extends to all members of the group (deleted the words on
"explicit and implicit"). (comment from Brian Weis)
A number of corrections, re-wordings and clarifications in
response to Kenneth Carlberg's email from 2 June 2009
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