Currently probetests take advantage of a number of assumptions about the SUT.
Unfortunately after some time with a working SAIO, configuration drift may
result in a system that is no longer compatible with these assumptions. To
help weary developers more quickly identify the changes they've made since
they last ran probetests successfully, some handy validators have been added
to test.probe.common
Additionally a new option 'validate_rsync' in test.conf, when enabled, will
run a series of up front validations during the setup of each probetest by
inspecting the ring, the mounted devices, and the rsync exports ("modules") in
order to ensure that when probetests fail the do so early and with specific
complaints.
To preserve existing failures, the option is disabled by default.
Change-Id: I2be11c7e67ccd0bc0589c360c170049b6288c152