client.shared.utils: Pylint/pep8 fixes

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
client.shared.utils: Avoid possible AsyncJob freeze

When AsyncJob process ignores SIGTERM, or custom kill function doesn't
kill the process properly, autotest hangs for infinity. This patch adds
additional kill -9 in case the process still lives after another
TIMEOUT time after kill_func execution.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
Merge pull request #822 from ldoktor/framework

client.shared.utils: Avoid possible AsyncJob freeze