Always request zeroed memory, in case we're dumb enough to leak it later.

Approved by:	re (gjb)
Export two new DCMD enums.  These allow set/get of the mfi_ctrl_properties
structure in the driver.

Having these in 10.0 means that mfiutil can be modified to take adavantage
of new updates without a kernel recompile.

Approved by:	re (gjb)
MFC after:	2 weeks
Launch the bourne shell using "sh" rather than "${SHELL}", as the latter
may come in from the environment and reflect the user's interactive shell.
Using bare "sh" is the dominant pattern in existing makefiles.

MFC this together with r255775.

Approved by:	re ()
MFC after:	2 weeks