Daide extension for requesting of best alternatives and sending best alternatives

[jnusrath]

What functionality will your new tokens add?
A new token might be added for sending a message requesting the Best Alternative proposal against a proposal that has been received. Another new token will be needed to send the best alternative to a previously sent proposal.

Describe the precise changes you'd like

• Using existing tokens, we propose two new tokens, such as BTR for the Best Alternative Request and BAT for sending the best alternatives.
• Daide clauses for these two might be “SND (power power…) (BTR(PRP(arrangement))” and “SND(power power…) ((PRP(new_arrangement)) BAT(PRP(prev_arrangment)))" for Best Alternative Request and sending best alternatives respectively.
• Example for BTR – if Germany sends Russia a request for the best alternative to the order proposal Russia sent before to Germany , the Daide clause might be “SND(RUS) (BTR(PRP(XDO(GER AMY BER HLD)))))”
  -Example for BAT - if any power sends Germany a new order proposal against a previous order proposal.
  THE DAIDE CLAUSE might be “ SND (GER) ((PRP(XDO(GER AMY BER HLD)BAT(PRP(PEC(RUS GER))))))“

Additional context
For the negotiation between agents, we are proposing a Daide extension.