ios xcode 6.0 update

this PR updates `ios xcode template` and `iOS+OFLib` for latest release of xcode 6.0

- standard architectures are now selected by default.
  - xcode 5.1.1 - these include (armv7, armv7s, arm64)
  - xcode 6.0 - these include (armv7, arm64)

ive set the valid architectures to 'armv7' only as thats the only architecture iOS-OF supports at the moment.
once apothecary builds are working, we can add `armv7s` and `arm64` to the valid architectures list.

this change is necessary as we are now moving to a 64-bit OF.
this also means that the minimum iOS version needs to be 5.1.1 as arm64 will not compile otherwise.
so ive made the necessary adjustments in `ios xcode template` and `iOS+OFLib` to make their build targets for iOS 5.1.1

have compiled and ran most iOS examples and its all looking good.
there is a deprecation warning in `ofxiOSAccelerometer` that `UIAccelerometer` is deprecated as of 5.0 but it still works, so we still have a bit of time to swap it out for a `CoreMotion` implementation.

have also tested xcode 6.0 backward compatibility by running these changes in xcode 5.1.1 and there is no issues.