Improve package dependencies

Remove uneeded dependencies to allow better support for dkms.
Change /usr/sbin to /usr/bin
Fix getting package version numbers

Get version numbers from zfs instead of spl-utils.

Fix uname -r
Add quote strings to bash variables

Contributed by graysky at https://aur.archlinux.org/packages/zfs-utils/
Add comment about bash variables in PKGBUILD

These scripts don't use them because AUR doesn't handle them properly.
Update to 0.6.2_3.11.6-3
Fix spl dependency version replace

Add new sed statement to replace this single occurrence.