Too many "SIGNATURE"s in D-BUS

[David A. Wheeler]

The term "SIGNATURE" has too many meanings.  It's
the type signature for a variant data value;
the type signature of the entire message
(whose type is also SIGNATURE), and if it's
secured it's the digital signature of the message.
Ugh.

I suggest changing the D-BUS type "SIGNATURE"
(code 'g') to "TSIGNATURE" in the
conventional name/code/description table for types,
and changing the heading field table so that
decimal code 8 "SIGNATURE" has the
conventional name "BODY_TSIGNATURE"
with the type "TSIGNATURE".

--- David A. Wheeler