sys/errno.h:  Fix whitespace
sys/errno.h:  Indirect EOPNOTSUPP via new ENOTSOP

This is how BSD does it.  Semantically, it makes more sense for an error
specific to sockets to be defined in terms of a general error than for a
general error to be defined in terms of a specific one.
sys/errno.h:  Define EILSEQ
Merge branch 'errnos'
Genie:  Fix MAP_FIXED error to ENOTSUP