*Proposed change* _data-tag values give vector length

[ramsdell@linus.mitre.org (John D. Ramsdell)]

As you all know, I prefer _data-tag less multiline tagged data
proposal, but let me suggest an improvement for the multiline proposal
with _data-tag.  I suggest making the tag values a non-negative
integer which suggests, but does not specify, the number of lines that
make up the multiline data.  If the constructor of message knows the
number of lines associated with a value, it sends it, otherwise it is
free to send zero.  In a Java implementation, this value would be
given to the Vector constructor when creating the initial empty
vector.  An MCP parser with a good guess as to the number of lines in
a message could save many vector allocations that come about due to
length overruns.

John