Make halo prove tests less racy

Summary:

Halo prove tests were racy in a couple of ways. First, they raced
against the self-heal daemon (e.g. write to volume with two bricks
up and then assert that only two bricks have data file; but shd will
properly copy file to third brick sooner or later). Fix by disabling
shd in such tests.

Second, tests rely on pings to complete and set halo state as
expected, but do not check for this. If writing begins before initial
pings complete, all bricks may be up and receive the data. Fix by adding
explicit check for halo child states.

Test Plan:

prove tests/basic/halo*.t

(prior to this changeset, would fail within ~10 iterations on my
devserver and almost always on centos regression. Now runs overnight
without failure on my devserver).

Reviewers:

Subscribers:

Tasks:

Blame Revision:

Change-Id: If6823540dd4e23a19cc495d5d0e8b0c6fde9a3bd
Signed-off-by: Kevin Vigor <kvigor>
Reviewed-on: http://review.gluster.org/16325
CentOS-regression: Gluster Build System <jenkins.org>
NetBSD-regression: NetBSD Build System <jenkins.org>
Reviewed-by: Shreyas Siravara <sshreyas>
Smoke: Gluster Build System <jenkins.org>