autotest/tp-libvirt — pull request #344 by waynesun09 (2014-10-16 03:59:05+00:00)
Title: blockcommit: Add active commit test cases

Since libvirt 1.2.4, active commit is supported, add test case to
cover this.
After snapshot and blockcommit, check the backing chain in disk
xml via backingStore element.

Signed-off-by: Wayne Sun