Fix chain_database_impl::clear_pending (#70)
Fix chain_database_impl::clear_pending (#70)

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