Treate kfreebsd like linux in most respects
kfreebsd has /dev/urandom
All platforms but Windows find hash in std::tr1
kfreebsd does not have <sys/prctl.h>
kfreebsd does not have tcmalloc
enable building packages on kfreebsd
Merge pull request #2 from jepler/debian-fixes-kfreebsd

Enable building on debian kfreebsd-amd64