Clarify documentation for format()
Clarify documentation for format()

Closes RAM-125.

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