[PATCH 3/3 V4] xfstests: btrfs tests for basic informational commands

[Rich Johnston]

Dave,

Sorry for skipping test numbers,  I was going to revert, correct the 
test number and resubmit this patch.
Do you want me to rename btrfs.filter to common.filter.btrfs when I
resubmit this patch?

Regards
--Rich