The splat module is only needed for the spl regression tests.
But if we add it to MODULES then 'zfs.sh -u' will be able to
unload it if needed, The downside if 'zfs.sh' will always
load it but it's overhead is minimal and in a production
setting you'll always be doing a 'modprobe zfs' anyway so
this is really just for testing.
The common.sh script assumed that it was either being run from
in-tree or was installed under /usr/libexec/zfs. If this was
not the case, because of say the default --prefix=/usr/local,
then the paths would be wrong. To fix this common.sh is now
generated from common.sh.in with the correct path information
provided at configure time.
Brian Behlendorf