Add a man page for the new function pmap_unwire().
Reduce per-LUN memory usage from 18MB to 1.8MB.

CTL never had use for CA support code since SPI has gone, and there is no
even frontends supporting that.  But it still was reserving 256 bytes of
memory per LUN per every possible initiator on every possible port.

Wrap unused code with ifdef's in case somebody even need it.

MFC after:	2 weeks
Increase maximal number of SCSI ports in CTL from 32 to 128.

After I gave each iSCSI target its own port, the old limit appeared to be
not so big.  This change almost proportionally increases per-LUN memory
use, but it is still three times better then it was before r268807.

MFC after:	2 weeks
Update to byacc 20140715 (only concerns regression tests being fixed)
Directly use regression test from upstream

PR:		191020
Submitted by:	gcooper (yaneurabeya@gmail.com)
Add the mtree entry for yacc tests
Merge remote-tracking branch 'upstream/master'
Fix markup regression introduced in r268369.
Merge remote-tracking branch 'upstream/master'