Use `NSUserDefaults` to communicate with UIAutomation in iOS 8.
Locate the simulator preferences on iOS 8.

With a different directory layout for simulator configurations
inside `~/Library/Developer/CoreSimulator/Devices` rather
than `~/Library/Application Support/iPhone Simulator`.
Fix typos in `simulator-set`'s documentation.
`simulator-set` only overwrites the simulator's version if one is specified.

`simulator-set`'s documentation describes the version argument
as optional.
Update `simulator-set` for Xcode 6.

In Xcode 6, the Simulator's device type and version are not stored separately
in the Simulator's preferences, but as a unified configuration (a "device")
identified by a UDID. To change the device type and version, we must thus determine
which UDID to set, which we do by examining the mapping provided by
`instruments -s devices`.

Similarly, the Simulator's content and settings are no longer stored
under version-specific directories, but under device-specific directories.
However, it's not safe to delete these directories directly--some devices
will not recreate them on launch. Fortunately, Apple has added a command-line
utility for managing devices.
Supply Xcode 6-format device specifications to `instruments`.
Force Xcode 6 to run OCUnit tests. (refs #258)
Support running Subliminal's tests against iOS 8 in CI.
Update UIAutomation's visibility bugs for iOS 8.

This also corrects the name of an existing test case in the visibility
test documentation.
Upgrade project settings for Xcode 6.
Pick up the latest OCMock to resolve Xcode 6 warnings.
Merge branch 'shared/Xcode6' of git://github.com/inkling/Subliminal into develop-new

Conflicts:
	Unit Tests/OCMock