webadmin: Add detect kdump checkbox to power mgmt config

Adds detect kdump checkbox to power management tab in Add/Edit Host
popup. If set host will be checked if it's not in kdump flow before
fencing execution.

Change-Id: I29bdf112c8d5e7dd19af4b2e77c52f07eb898d47
Bug-Url: https://bugzilla.redhat.com/1079821
Signed-off-by: Martin Perina <mperina@redhat.com>