The Ioctl extension

The idea is to have an easily extensible module for getting the value
of the C Ioctl constants.

The .xs file is automatically rebuilt from the Ioctl.def and xsproto
file, and likewise the .pm file is generated from Ioctl.def and
pmproto. Any local additions that need to be included should go in
Ioctl.def (where, incidentally, they won't be wiped out if you install
a new version on top of this one.)

No symbols are exported by default.  You need to name each symbol you
want ("use Ioctl qw(TCFLSH TCXONC);".) You can also directly refer to
unexported constants via "Ioctl::SymbolName".

Genconst.pl also supplies constants and preproccesor/C code. Any
changes to the master distribution will be made there, but any site
local changes should be made in Ioctl.def. This way, genconst.pl can
be patched in future, while leaving your local improvements/munging
alone.

- Ken (kjahds@kjahds.com, CIS:70705,126)
