Log errors from ScheduledThreadPool executors.

[mansu]

Currently, we schedule tasks using a ScheduledThreadPoolExector. When using this one has to be careful wrap all Runnable.run() methods in a try/catch block. If we fail to do that the repeating task fails to run after the first failure.

A smarter way is to use a loggingScheduledPoolExecutor like this one: https://github.com/apache/aurora/blob/c85bffdd6f68312261697eee868d57069adda434/src/main/java/org/apache/aurora/scheduler/base/AsyncUtil.java