mdadm: detailed information on out-of-sync drives

Old message:

	mdadm failed device md1

New message:

	mdadm failed device md1: sda2 (faulty), sdc2 (faulty)
mdadm: rescue from potential exceptions
tw_cli: support multiple controllers

* support multiple controllers
* simplified a bit
Merge pull request #7 from artyom/master

mdadm: detailed information on out-of-sync drives