add slide / presentation links to HBaseConf 2015
add slide / presentation links to HBaseConf 2015

SteamShon/incubator-s2graph,SteamShon/incubator-s2graph,jongwook/incubator-s2graph,daewon/incubator-s2graph,SteamShon/incubator-s2graph,jongwook/incubator-s2graph,daewon/incubator-s2graph