IMPALA-3114: Add a pause monitor for impala processes.
IMPALA-3114: Add a pause monitor for impala processes.

This commit adds a simple pause monitor to the impala processes.
This pause monitor launches a single thread that sleeps for 500ms,
wakes up and checks the actual time slept. If it exceeds 10s, a
warning is logged. This is very useful for debugging hardware/OS
issues which can cause process hangs.

Change-Id: I04eca63c0c44fa8f1b78833080acdc2176372263
Reviewed-on: http://gerrit.cloudera.org:8080/2405
Tested-by: Internal Jenkins
Reviewed-by: Bharath Vissapragada <f23dbca75acdac4082d6a05c290fc03565dada86@cloudera.com>

ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC