Pull in changes needed to fix tests for 10-CURRENT

This fixes some of the initial items needed in order to make the tests pass a bit more cleanly on CURRENT with UFS/ZFS:

FreeBSD gran-tourismo.west.isilon.com 10.0-CURRENT FreeBSD 10.0-CURRENT #2 r+6fb31dd: Tue Mar 12 16:10:51 PDT 2013     gcooper@gran-tourismo.west.isilon.com:/usr/obj/usr/src/sys/GRAN-TOURISMO  amd64

Feel free to drop the requires_root commits as they're not critical to fixing/improving things with the test suite.