error is returned all the way back to the dtrace app, it's hard to
figure out where that error came from.
Add a couple of functions to get and set the error location which can
be optionally compiled into the library.
* Handle the different ioctl design.
* Support the freopen() changes.
* Use functions in FreeBSD's process library rather than the CDDL
library that Solaris has which sits on top of their process file
system and is therefore unsuitable for use on FreeBSD. The libproc
API for FreeBSD is deliberately different to that on Solaris because
Sun wouldn't release the libproc.h header under a BSD license.
* On FreeBSD define both LITTLE_ENDIAN and BIG_ENDIAN and then set the
BYTE_ORDER to the one we are using. On Solaris they define one or
the other but not both. For us to keep using FreeBSD header files,
we need to use endian definitions the same way we do in pure BSD
code.
