Subliminal aborts the run if the simulator is in an inconsistent state.
(closes #147)

In certain environments like Travis, `instruments` intermittently hangs.
When this occurs, it seems that the simulator is also in an inconsistent state
such that it can't be rotated, web pages don't load, etc. If we detect that
we are running in such an environment, Subliminal aborts the run after logging
an error. `subliminal-test` detects this error and retries.
`subliminal-test` maintains the previously set device type/version when it resets the simulator.
Merge pull request #148 from inkling/jeff/debug_stall

Abort and retry when `instruments` launches the simulator in an inconsistent state.