Initial version of PKCROSS implementation

["KAMADA Ken'ichi" <kamada@nanohz.org>]

Hello all,

I have put the initial version of our PKCROSS implementation for
Heimdal at <http://www.taca.jp/krb-cross-realm/pkcross-heimdal.html>.

This is a patch for Heimdal 1.0.1 in the svn repository
<svn://svn.h5l.se/heimdal/tags/heimdal-release/heimdal-1.0.1>,
*not for the released tar ball*.

Please note that a serious deployment is premature, because some
incompatible changes are expected in accordance with the progress of
standardization.
- The format of ticket extensions is tentative and will be changed.
- Several unregistered parameters are used (ETYPE_EXTENDED_TICKET,
  pkcross KDCOption, etc).

Any comments are welcome.

Thanks,
-- 
KAMADA Ken'ichi <kamada@nanohz.org>