d4ec037fix rabit6612fcfMerge branch 'master' of ssh://github.com/tqchen/rabitd29892cadd mock option statis4fa054enew tracker75c647cupdate tracker for host IPe4ce8efadd hadoop linear example76ecb4aadd hadoop linear example2e1c4c9add hadoop linear example git-subtree-dir: subtree/rabit git-subtree-split:d4ec037f2e