Add includes of referenced SAIO bin scripts

Change-Id: I6810e69a757336a3aed0a38146c27f270fe2dde1
Merge "Add includes of referenced SAIO bin scripts"
Load constraints from cluster info dictionary

If the target swift cluster under test offers the /info API, use the
constraints derived from there. If it does not, then pull constraints
from /etc/swift/test.conf, defaulting to an existing
/etc/swift/swift.conf, as we used to.

Change-Id: Iea01c9c4b5148faa10004a240df411cbe7336a6a