Create the first 0.6.0 release candidate tag (rc1). The Posix
layer is now functional and passes fstest and several other
test suites cleanly. We now need this release candidate tag
to broaden the test coverage before we can release the official
zfs-0.6.0.
Add autoconf style build infrastructure to the ZFS tree. This
includes autogen.sh, configure.ac, m4 macros, some scripts/*,
and makefiles for all the core ZFS components.