[crossfire] Wraith patch committed. Please test.

[Anton Oussik]

The wraith patch has been merged into the source tree. It will most
likely need some tweaking to make it balanced, most notably the
strength of the feed skill and proportion of that returned to the
player as hp/food: on one hand we want it to be possible to survive by
feeding off things, on the other hand we do not want to be able to go
run-feeding through hordes of orcs at level 1.

Please test it and comment on changes to it you would like to see.

The details of the patch and the patch itself can be found here:

https://sourceforge.net/tracker/index.php?func=detail&aid=1382884&group_id=13833&atid=313833