XCTest Bundle Support

Based off of jeffh/xcode5-compat #120.

- Adds an XCTest bundle target and a new scheme (for OCUnitApp target) to run the new test bundle.
- The rake file will conditionally run the XCTest bundle only if running under SDKs >= 7.0.
- Runs XCTestSuites in unison with Cedar specs (like SenTest/OCUnit).
- Updated CDROTestReporter to use the example names for class-like output. This fixes #56811794 on tracker.
- Updated CDRSymbolizer use Xcode's internal atos tool, allows it to symbolize arm7s (and arm64?). See http://stackoverflow.com/questions/13227747/does-atos-not-supports-armv7s