Add new Protocol Buffer message RecoveryPartition into repo.
Add new Protocol Buffer message RecoveryPartition into repo.

The purpose of RecoveryPartition is to provide communication
protocol between coordinator and recoveryMaster during crash
recovery. RecoveryPartition goes both directions during a
recovery, which means coordinator sends it to recoveryMaster,
and recoveryMaster will send it back to coordinator.

rstutsman/RAMCloud,behnamm/cs244b_project,y-higuchi/ramcloud,DavidLi2010/ramcloud,y-higuchi/ramcloud,DavidLi2010/ramcloud,alexandermerritt/ramcloud,behnamm/cs244b_project,jblomer/ramcloud,jcarreira/ramcloud,y-higuchi/ramcloud,behnamm/cs244b_project,SMatsushi/RAMCloud,jblomer/ramcloud,matrix207/RAMCloud,QingkaiLu/RAMCloud,SMatsushi/RAMCloud,DavidLi2010/ramcloud,anirajk/RAMCloud,alexandermerritt/ramcloud,utah-scs/RAMCloud,y-higuchi/ramcloud,behnamm/cs244b_project,anirajk/RAMCloud,y-higuchi/ramcloud,SMatsushi/RAMCloud,mrdiegoa/ramcloud,utah-scs/RAMCloud,rstutsman/RAMCloud,anirajk/RAMCloud,rstutsman/RAMCloud,alexandermerritt/ramcloud,behnamm/cs244b_project,QingkaiLu/RAMCloud,jblomer/ramcloud,utah-scs/RAMCloud,anirajk/RAMCloud,IMCG/RamCloud,jcarreira/ramcloud,DavidLi2010/ramcloud,DavidLi2010/ramcloud,alexandermerritt/ramcloud,mrdiegoa/ramcloud,y-higuchi/ramcloud,jcarreira/ramcloud,mrdiegoa/ramcloud,QingkaiLu/RAMCloud,IMCG/RamCloud,mrdiegoa/ramcloud,rstutsman/RAMCloud,matrix207/RAMCloud,utah-scs/RAMCloud,jblomer/ramcloud,DavidLi2010/ramcloud,alexandermerritt/ramcloud,QingkaiLu/RAMCloud,jcarreira/ramcloud,utah-scs/RAMCloud,behnamm/cs244b_project,SMatsushi/RAMCloud,rstutsman/RAMCloud,mrdiegoa/ramcloud,rstutsman/RAMCloud,SMatsushi/RAMCloud,IMCG/RamCloud,jblomer/ramcloud,SMatsushi/RAMCloud,alexandermerritt/ramcloud,matrix207/RAMCloud,matrix207/RAMCloud,anirajk/RAMCloud,utah-scs/RAMCloud,IMCG/RamCloud,mrdiegoa/ramcloud,jcarreira/ramcloud,IMCG/RamCloud,matrix207/RAMCloud,QingkaiLu/RAMCloud,anirajk/RAMCloud,QingkaiLu/RAMCloud,IMCG/RamCloud,jcarreira/ramcloud,jblomer/ramcloud,matrix207/RAMCloud