Add market_engine::cancel_all_shorts
Add market_engine::cancel_all_shorts

bitshares/devshares,bitsuperlab/cpp-play,camponez/bitshares,RemitaBit/Remitabit,frrp/bitshares,jakeporter/Bitshares,Ziftr/bitshares,bitshares/devshares,bitshares/bitshares-0.x,RemitaBit/Remitabit,bitshares/bitshares-0.x,bitshares/bitshares,RemitaBit/Remitabit,FollowMyVote/bitshares,FollowMyVote/bitshares,frrp/bitshares,bitsuperlab/cpp-play,jakeporter/Bitshares,camponez/bitshares,dacsunlimited/dac_play,RemitaBit/Remitabit,bitshares/devshares,bitshares/devshares,bitsuperlab/cpp-play,bitshares/bitshares,camponez/bitshares,RemitaBit/Remitabit,bitshares/bitshares-0.x,bitsuperlab/cpp-play,jakeporter/Bitshares,FollowMyVote/bitshares,bitshares/bitshares,dacsunlimited/dac_play,dacsunlimited/dac_play,bitshares/bitshares,frrp/bitshares,dacsunlimited/dac_play,camponez/bitshares,bitshares/bitshares,dacsunlimited/dac_play,bitshares/devshares,Ziftr/bitshares,frrp/bitshares,jakeporter/Bitshares,dacsunlimited/dac_play,frrp/bitshares,bitsuperlab/cpp-play,Ziftr/bitshares,FollowMyVote/bitshares,bitshares/bitshares-0.x,FollowMyVote/bitshares,Ziftr/bitshares,bitshares/bitshares-0.x,jakeporter/Bitshares,bitshares/bitshares-0.x,jakeporter/Bitshares,FollowMyVote/bitshares,camponez/bitshares,RemitaBit/Remitabit,bitshares/devshares,camponez/bitshares,bitsuperlab/cpp-play,frrp/bitshares,bitshares/bitshares