YARN-2673. Made timeline client put APIs retry if ConnectException happens. Contributed by Li Lu.

(cherry picked from commit 89427419a3c5eaab0f73bae98d675979b9efab5f)
YARN-2582. Fixed Log CLI and Web UI for showing aggregated logs of LRS. Contributed Xuan Gong.

(cherry picked from commit e90718fa5a0e7c18592af61534668acebb9db51b)