Heads up: OFED build by default

[Konstantin Belousov]

I am going to merge revisions r336568, r336569, and r336570 from HEAD to
stable/11. They enable the build of the OFED libraries by default, and
move the build of most of the utilities under the WITH_OFED_EXTRA knob.
Also as a minor fix, since libpcap lives in /lib and depends on two OFED
libraries, these libraries are moved into /lib.

I do not expect that any user of stable/11 would be seriosly affected by
the change.  Small detail is that / filesystem becomes somewhat larger.
Slightly bigger detail is that if you really need OpenSM or some of the
utilities, you should use WITH_OFED_EXTRA instead of WITH_OFED knob.