This commit introduces the hpssa module. The module has
the ability to parse the current raid configuration and
hardware details of the server. It also has a manager
which has ability to create/delete/get raid configuration.
For now, create is limited to machine-dependent configuration.
Each logical disk to be created will require the controller
and physical disks to be used.
Change-Id: Ib58620d8d4f47eb55c55c6abb5d3b294623205bf
Implements: blueprint hpssa-support